Experience a different way to stimulate your nipples or for that matter, your cock head or "other" erotic body parts.  You can choose to use them as a vacuum electrode by slightly squeezing the air out of them over the "target", pushing them onto the skin firmly  and then releasing to create a good seal.  Before using, add a small amount of water or water based gel on the sponge to move the current from the top connection to the inside conductors and to the sponge.  Be sure to take the wet sponges out and rinse clean and let dry before placing them back into the housing.  You do not want mold to develop on the underside of the sponges or inside a wet housing.  You can always replace the sponges by purchasing a thin sponge at any retail or grocery store and cut them to fit inside the housing. 

Being curious, as most of us are, we decided to take a look inside these electrodes to see how they function electrically.  Here is what we saw and found.

 After removing the small sponge, there is a metal disk that pushes gently on the wet sponge moving current from the connection to it.

    Moving the disk aside, we see that there are three springs inside that are used to gently and evenly push the disk up to and make good contact with the sponge.  The springs are connected to the top of the soft silicone housing with a female TENS connection connected to another small disk.  Simple and effective.

    Put back together, it again looks like this.

The dimensions for these electrodes are shown in the picture below.  

  The inside diameter is right a 1.5" and the height is about the same, 1.5".  A TENS pin is inserted into the side of each electrode from your lead wire (not included).

NOTE: These are single-pole electrodes and it takes two electrodes to complete the circuit. For safety reasons, do not connect both electrodes to one lead and place these on each nipple.  Current can run across the chest and could cause a heart malfunction.  You can attach one to a nipple and use a TENS pad or similar electrode next to it to complete the circuit.  Thus, two cups, one on each nipple and one TENS or similar electrode next to the nipple.  Two lead wires using both channels for two nipple connections.

Using below the belt you can use your imagination and inginuity.  :) 

Do not use these above the waist if you have any electrical/electronic medical device implanted, such as a pacemaker.

Also, do not estim if you are pregnant.