Amazing either with a playmate or solo.
zOMG this is the bomb! The perineum electrodes don't make very good contact and so prickle unpleasantly if used, but the main electrodes produce an amazing rhythmic contraction at higher settings. Super nice without the controller too and OMG when it first slides in... Just don't bother with the perineum electrode ports.
This thing feels like it is just made to fit up your arse once you get it over half-way in, your bum literally sucks it snugly into place and presses it against your prostate. The internal electrodes deliver an almost burning but highly pleasurable buzz deep up your bum while the external electrodes intensely electrify the base shafted of your cock.