This automatic penis pump is easy to use, and packs a ton of power! Slide into the silicone sleeve using a little water based lube for sleekness. The tight opening will Crete a seal around your penis so that pressure can build within. The cylinder is textured for a firm grasp, clear so that you can watch yourself grow, and marked with measurements so that you can track your progress. Explore 5 levels of suction, finding your perfect amount of pressure with the plus and minus buttons. Measurements: 11.5 inches in total length, 8 inches insertable cylinder depth, 2.35 inches in diameter. Silicone opening is .75 inches in diameter, un-stretched. Hose is 8.75 inches in length. Charges via USB