The Rear Rocker is sized nice and (not too) big, filling and deeply stimulating fans of a sexy anal stretch. It's smooth and tapered up top, maxing out in width toward the bottom. Like any good butt toy, the big base is wide and distinct, preventing too-deep slips and letting you play worry-free. 
If/when you or your partner is in the mood for some rumbly vibration, one single button at the base of the Rocker activates and cycles through ten wild, toe-curling modes of powerful vibration.
In hypoallergenic, body safe borosilicate glass, the Rocker is extremely hygienic and easy to clean using warm soapy water or a good toy care fluid/foam. You will, of course, be using lots of lube with this and any anal toy, so please stock up beforehand.