REVHAMMER shaft-strapped shaker is a c-ring plus shaft-ring that puts the vibe shaft-wise, length-wise up on top. Its got a rubbery front nub that seeks to aim at any holeREVHAMMER sends vibe into the both your shaft and the lucky shaftee. REVHAMMER straps on with a rubbery c-ring in back, the vibe lays on top and the front ring stretches around your shaft about 1-1.5 from the base. The rings secure the reverb-vibe for lots of hard play. VIBE UNIT: 3 button batteries give 5-7 hours buzzfucking vibing. Battery size: LR44, comes with three. Hnkyjunk PLUS+silicone TPR/silicone blend: silicone for a smooth and warm feel, TPR for amazing stretch and strength. Phthalate free. LUBE SAFE: Water-based lube, hybrid or silicone lube, oil-base lubes not recommended. CARE: Wash after use in warm soapy water, air dry. Store toys separately :we recommend storing in breathable cloth pouches or for larger toys, in cotton socks.