www.e-stim.net

DIY low profile (builds only 2-2.5mm from base) 4mm connectors for E-Stim insertibles.
I also used some slim 4mm female connectors, silicon insulated wires and shrinkwrap - very comfortable

You may get them from here: https://hobbyking.com/en_us/5mm-male-go ... s_products
Or do a general search for 4MM low profile banana plugs

PelleParafin

Nice work. The plugs and connector parts are pretty cheap on eBay:
https://www.ebay.co.uk/itm/202742857117
https://tinyurl.com/yxt3hy99

Very well done.

Similar plugs are also offered as RC charging cables. The cable is already connected to the low profile plug. On the other side, you only need to cut off the superfluous plug and screw or solder on a suitable female plug.

Here is a source in Germany:

https://www.marfitec.de/Ladekabel

I'm sure you can find these Charging cable in other countries too.

Deltus

I purchased this back in 2016, still working great.
Only 5.99 US$
https://www.progressiverc.com/products/ ... -extension