Hammerhead Masturbator Attachment is made using phthalate free Thermoplastic Rubber TPR. Male masturbation device is compatible with most silicone or water-based lubricants. Masturbator measures 4 inches long (9.5 cm). Outer circumference 5.75 inches (14.6cm). Inner diameter of bumby side 1.5" Ridged inner side is 1" The Hammerhead Masturbator is a soft, stretchy massager wand attachment for men that delivers intensely pleasurable fluttering and sucking sensations when you slide the snug fitting sleeve back and forth along the shaft of your penis. Clear stroker lets you view as you stroke. For use with the VibeRite Personal Massager. Sold separately.