Electric Prods are an advanced electrical toy. Prods are unipolar products so they must be used with another toy which is in contact with the body. The tip of the prod is reversible. One end of the tip is dull and is useful once a sweat has been worked up. The other end of the tip is rather sharp, which makes it useful to penetrate clothing (even denim) or even the outer surface of dry skin. CAREFUL: Only slight pressure is required to penetrate the very thin surface layer of skin to feel the electrical contact. Be very gentle with this toy, its very small surface area which contacts the body can make it an intense device. Compatibility: This product works directly with folsom and erostek units. This product is compatible with Rimba units when you purchase the pins to banana adapter (sold separately).