What a powerful stroker pump! This powerful stroker pump features multi-speed vibrations with powerful robotic stroking action and a Silicone soft noduled pleasure sleeve for a secure vacuum seal. The medical style suction bulb has a quick release purge valve for safety. Stroking Power Pump measures 13â tall with a diameter of 3.5â and a cylinder depth of 8â . Use 4 C batteries, not included, for delightful stroking action. This penis pump is sure to promote lengthening, thickening, stamina, and increased orgasms. A hygienically superior Silicone tapered sleeve provides a secure vacuum seal at the base of the unit. Get unbelievable results with the BlackJack Stroker!