Quite pleasant actually, the best inflatable plug I've tried so far (ok, I've only tried two). Unfortunately it's got an issue: it's not made of a non-porous material, so it picks up smells. Which is a bad thing in a toy designed to go up your bum. It's not quite at a horrific level, but it's far from optimal. A shame, really.
Soft silicone material. Pump is detachable.