The accessories on this page are sold to accompany the ElectraStim power boxes and kits in the "sexpacks" section. To help with your choice:
"Uni-Polar" design means that you need to use these items with another accessory such as an ElectraRing, ElectraLoop or ElectraPad for twice the fun!
"Bi-Polar" design means that these items can be used for vaginal or anal insertion without the need for any other accessory. Bi-polar probes are generally used as an independent electrode but can be used in a uni-polar set-up by combining them with another accessory such as a cock ring or loop. Instead of connecting both cables to the probe, just connect one and connect the other end of the cable to a ring or loop. This will give the stimulation in both areas for a double-whammy experience - this applies to all bi-polar probes.