By adding 3/4" diameter electrode studs to the bottom of this Silicone (TPR) ball sack you will have hours of fun and if you wish inflict some pain to the wearer.  Maybe your boy needs to be taught a lesson or you might just want to experience your balls shocked into a cumming frenzy.  :)  Either way, you will have a good time trying.

The pictures below show the profile of the product, but without the electrodes protruding from the bottom.  

Add some water based or electrical gel inside the bag and simply fit the penis through the top compartment stretch and slip the silicone chamber over the boys to create a nice tight fit.  Once all is in place, just squeeze what little air might be left inside out of the top opening to create a soft vacuum sensation and to make good contact with the two electrodes.  This device is just a little smaller than the OxBalls SackSling for those who require a tighter fit.  The ring around the base of the penis will also act as a great cock ring for a stiffer, harder member when erect. Most of us were not lucky enough to have balls that hang to our knees, so this ball sack is perfect for many.  :)

Made from TPR, the Master Series Line of toys are body safe and a great choice for everyone. Just add your favorite Water Based Lubricant and have a wet n wild time. It is not recommended to be used with silicone lubes. After use, carefully wash the toy with mild soap and water or your favorite toy cleaner. 

The electrodes are connected at the bottom using ordinary TENS pins.  A 2.5mm lead with TENS pins is included with the package, but you may not need it if you have a power box that uses ordinary TENS leads or has a 3.5mm lead with TENS pins for connections.  2.5mm audio jacks are typically used with Rimba and Zeus power boxes.  

The dimensions of this product are as follows (shown without electrodes):