Serious Kit Electro SPT And V2K Conversion Kit (Or Pimp My Tremblr)

Written by  Jan 13, 2021

A guest review of some serious penis play kit

I am delighted to bring you a guest review from RubberStimmer, a long time stimmer and rubber fetishist. I love hearing about new pieces of sex tech and the SPT, and V2K conversion kit has me experiencing a little bit of penis envy. I can only imagine how good they must feel.

This kit is designed to improve the performance of the Venus 200 and Tremblr male masturbators and I hope you enjoy this guest review as much as I did.

"If you like long edging sessions, this is an excellent addition to your toy bag. Unlike the SK system, a column milker is easier to use solo, and cleanup effort is just the receiver."


Guest Reviewer - RubberStimmer

The Serious Kit Electro STP or receiver was designed for their now iconic, milking system.

A piece of kit that I suspect plays a part in the fantasies of many, but more often than not it is out of reach.

Serious Kit Electro SPT and V2K conversion kit (or pimp my tremblr)

The Serious Kit Electro STP or receiver was designed for their now iconic milking system. A piece of kit that I suspect plays a part in the fantasies of many, but more often than not it is out of reach. A full Serious Kit (SK) system is a significant investment in both money, space and time. However, it is (I'm told) a seriously amazing experience.

Based on an actual milking machine for animals, suction in a serious kit milker can be applied two ways. First into the chamber where your penis is inserted and the second is behind the liner sleeve that acts as flexible diaphragm.

This second style of suction is often referred to as a column milker where all the liquids are contained in the receiver sleeve to protect the pump. When the pump operates the liner sleeve collapses and expands. This pressure difference, providing there is a good seal creates a small vacuum and milks you. Venus2000 (V2K) and the Tremblr are both column milkers. They are cheaper, take up less room but don't have the ability to suck from inside the receiver.

The sensations between the two types differ. An SK milker is a sucking sensation pulling you inside the receiver. Whereas on the Tremblr and V2K the receiver (mostly) slides up and down providing a stroking sensation.

Of the Serious Kit range of SPT's only two are highly compatible with Tremblr and Venus 2000 (V2K) milking machines: the standard SPT and the Electro SPT. Other SPT's rely on suction from within the chamber. They can be used with a fluid trap however getting moisture inside a Tremblr or V2K pump mechanism is likely to dramatically reduce its operating life.

Serious Kit is a modular system, you can select what you need and then add later on but as a minimum if you want to pimp your tremblr/V2K you need to get an SPT and the conversion kit. Yes, you could create your own conversion but a quick calculation of the bill of materials shows the conversion kit is pretty good value.

The Electro SPT

Image showing RubberStimmer enjoying his kitAdding estim to milking provides a totally new dimension of sensation. The Electro SPT is a monopolar electrode that is connected via a 4mm banana socket. An elasticated loop is provided to suspend the SPT either from an overhead frame or from the Serious Kit harness while seated or standing.

Finally, there is an inlet tube for the continuous lubing system that is the one big advantage of a the SK system over column milkers. Excess fluids are sucked into the milking machine away from the pump. This allows for longer uninterrupted milking sessions. The tube is closed off with a crimp styled clip. At first glance to a V2K or Tremblr user this feature seems to be of limited benefit.

After some testing found that a 30ml syringe can be attached and used to inject lube into the receiver mid-session. There are some caveats; you have to keep it vertical, not use too much lube and slow the stroke right down. Adding too much lube while running too fast can squirt it out the air vent a surprising distance. Yes; I got lube all over my face so you don't have to.

Electro SPT's come in 3 sizes 30, 40 and 50mm with a matching conductive rubber liner. Replacement liners are available from Serious Kit either singlely or in packs of 3. There is no reason why you could not convert the SPT to non-electro with the right sized silicone liner.

Monopole electrodes need a second pole to complete the circuit so you will need to either use a triphase configuration with a bipolar anal plug or a single pole electrode. A pad could work however the sensation in estim is always stronger at the smaller contact surface. The SPT provides a large surface. I found that using an estim systems MJ with the head as common felt best but a moaner/large flo worked nearly as well.

Image showing the Serious Kit SPT and harnessThe look and finish of the Electro SPT is fantastic. Bright polished aluminum and a clear cylinder. When it is operating you can see the liner sucking you into the receiver vacuum wrapped in black conductive rubber.

Venus 2k conversion kit

The kit is designed to convert a SK style SPT to a column milker and brings some extra features. Unlike a Tremblr or V2K receiver an SPT has two connection points for the receiver and column vacuum lines. The conversion kit has two connection lines with a quick disconnect. Each line has a tap to allow you to balance or turn off suction. The receiver line has a relief valve to vent excess fluids and a small moisture trap to catch any liquids coming out of the receiver if you open that tap to make it sort of a SK like experience. To be honest I started out a bit conflicted about the second line. After a few uses found that it is really useful for sucking the receiver on (and it feels good). Depending on how you are positioned the chances of fluid entering the pump is lower but not zero. It is also likely that when you most need to quickly close the tap as fluid is leaking in you are least likely to notice it.

Note for Tremblr users: The supplied line for the V2K conversion kit is 8mm silicone. No matter how hard I tried I could not get it attached to the Tremblr port even with warming the tubing. In the end I got a 9mm to 9mm automotive joiner and zip tied a short section of Tremblr hose on one side and the short V2K converter tail on the other.

Using the SK receiver

Most more complex equipment has a learning curve and often you need to improvise to get a great experience. Unlike a Tremblr or V2K receiver an SK SPT is quite heavy. For optimal operation it needs to be suspended. Harnessess are available but for the standard electro SPT there are frequent pop off issues (more on this in a separate review).

Testing out various options, the best approach seems to be suspending it just grazing your pubic bone. Some people use ceiling mounts but what works best for me is a boom stand that allow use both seated and reclined. This uses the weight of the receiver to keep it positioned perfectly.

You also need to be careful about suspending the vacuum hoses. Keeping them free enough to move around, but not so loose that the exhaust valve will pinch. SK sell a suspension kit to help with coming up with a workable solution but you still need to put some work and additional investment in.

Getting the right lube can be hard. I've settled on a combination of water based Swiss navy with 2 big squirts of estim systems electrogel smeared near the mouth of the receiver.

So how does it feel?


The super smooth liner of the Electro SPT is a soft embrace. Running it slowly with triphase adds a new dimension to estim. No longer is it just sensation, you can get the slide as well. There are some interesting effects as you play with the level of estim. Down low the stroking sensation is really apparent with estim providing some variation but as the stim level gets higher your perception of the stroke can disappear.

Here it gets really interesting. Unlike many cock electrodes it has a really big surface area that encompasses most of the penis. Running Triphase the perception of the pleasure sensation can shift quite dramatically to inside the body. The best was to describe it is that you no longer feel like have a cock, instead there is a larger area of stimulation centered on the front of your body. After checking with a couple of other people, it is not my imagination they feel something similar. Seems ironic that a cock milker can do this, but it opens up some really interesting play possibilities shifting between stroke and sensation.

If you like long edging sessions this is a great addition to your toy bag. Unlike the SK system a column milker is easier to use solo and cleanup effort is just the receiver.

Shipping and buying experience

The new Serious kit website makes shopping easy. You need to size the SPT correctly, so check your measurements and get as close as possible. Shipping was discreet in a plain brown box. Keep in mind at the time of this article SK does flat rate shipping for non UK addresses and it was a significant cost. If you are planning to add a harness or cables save up and make a single purchase. Liners are the exception with cheaper shipping.

The Serious Kit SPT Electrode is as its name suggests extremely capable and it provides unique sensations that tease, stimulate and satiate. Get one from @Seriouskit2 Click to Tweet

Key Features

Key features:

  • Adds slide to estim sensation for an incredible feeling.
  • 3 SPT sizes.
  • Uses 4mm plugs.
  • Liners can be replaced.
  • Conversion kit expands what your Tremblr/V2K can feel like.
  • Amazing build quality.

Final Thoughts

By combining both the sensation of estim and the slide of a milker you get an amazing experience.

It is almost addictively pleasurable, but it is not a toy for beginners.

You need to have a comprehensive toy box and a good foundation in estim to bring out its best.

For serious players it is a serious bit of kit for serious pleasure.

The Electro SPT and V2K conversion kit was purchased directly from Serious Kit.

Thank you RubberStimmer

I'd like to thank RubberStimmer publically for taking the time to write this review for everyone. It has certainly opened my eyes to the Serious Kit range of products, it sounds like the perfect addition to a serious stimmers tool box.

Where Can I Get One From?

Serious Kit

Grab one of these extremely effective pieces of equipment direct from Serious Kit for £165.

Check them out and don’t forget to tell them that Joanne says "Hi".


This review does not contain affiliate links, for more information about affiliate links check out my disclosure page.

Additional Info

  • Overall Rating: 9.0
Joanne Summers

Sex Blogger, Review, Dildo Officianado, Kinky Quimsticking, Electrosex Loving Mum.

I've been reviewing sex toys and adult products for the last seven years and I love doing what I do. Recently I have been designing my own range of e-stim electrodes.

If you find my reviews and articles interesting please leave a comment for me on them, I love reading feedback about them. Or alternatively you could Buy Me A Coffee, wink, wink.


  • Paul
    Comment Link Paul Wednesday, 13 January 2021 20:19

    This looks great....will need to save a lot :-)

  • Joanne Summers
    Comment Link Joanne Summers Thursday, 14 January 2021 08:38

    It is an expensive piece of kit but just the thought of it puts a smile on my face. It is definitely top end kit with performance to match its price tag.

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