Mystim Cluster Buster Wireless Remote Control E Stim Set Drinking The rings are also large The rings are also large enough to accommodate other BDSM accessories like rope and alternative restraints (sold separately) for more versatile play then compress the pump's bellows and let the water pressure work its magic Both the Cluster Buster + Sultry Sub are simultaneously rechargeable via the dual cable The Cluster Buster is compatible with an unlimited number of Sultry Subs (extra Channel 2 Sultry Sub units sold separately) across up to 10 channels so you can operate all the Sultry Sub units in each channel with separate e shock functions per channel