Arcwave Pow is a premium manual stroker with suction control, textured CleanTech Silicone sleeve and dual entry. Pow's intuitive silicone tightens pleasurably during use, while the air pressure release valve creates intense suction for a new and incredible climax. Air pressure release valve tightens the silicone sleeve, creating a controllable, natural suction sensation without batteries. By placing a finger over the air pressure release valve during use, you can control the suction intensity exactly to your liking