You control the pressure until desired effect with the EZ squeeze handle with pressure release valve.Features: Material_ Silicone (Soft Base and Hose), Polystyrene (Clear chamber), ABS (Gauge, Pump, Remote and Bullet) Size_ 11.75 (Total length), 2.5 to 2.6 (Cylinder diameter at base), 7.87 (Insertable length)2 AA batteries