Apollo Automatic Head Pump: the best head pump we have ever tested it will blow your mind! The American Pumpers Association. Easy to use, incredible suction. Automatic pressure control with the push of a button. Auto start/stop button. Quick air release button. Ergonomic hand-held controller with push button controls. Easy to read LED display measures PSI vacuum inside compact cylinder. Flanged base for a secure seal. Body safe donut. Safe and pure for body and pleasure made using phthalate free materials polycarbonate PC cylinder, ABS plastic with polyurethane PU Cote controller, Thermoplastic Rubber TPR donut, Silicone hose. Pump requires 4 AAA batteries, not included. Bulk weight 8.2 ounces. 4 inches by 2 inches cylinder.