Prepare yourself for larger, thicker erections with Rock Solid's Boost It Penis Pump. This pump's clear vacuum cylinder allows you to track your growth with each pull of the lever. Its silicone entry sleeve keeps the pressure in, and its easy-release button gives you the ability to move on to your next endeavor.Features Creates Thicker, Harder Erections Clear Vacuum Cylinder with Centimeter Markings to Track Progress Soft Silicone Sleeve for Airtight Seal Air Release Button for Fast, Safe Removal Pressure Meter Gauge to Track Results Phthalate-Free, Body-Safe Dimensions Total Length: 12 in. (30.5 cm) Insertable Length: 8 in. (20.3 cm) Unstretched Inner Diameter: 2.75 in. (70 mm) Circumference: 7.75 in. (19.7 cm)