Unipolar Hand Massager Textured Grenade

A very interesting toy.  It is unipolar so must be paired with something else. This is rare among insertables. It is textured for increased sensation... length is 3 1/4 inch, diameter at widest point is 1.5 inches. 

One photo is next to a standard #2 pen for size perspective. 

Plug a standard 2mm pin into either end. Be sure to use a string around it or some other method for retrieval if the pin comes out.