First released in 2006, Tenga is a Japanese manufacturer of innovative masturbation sleeves. Originally specializing in one-time up masturbation toys (onacup), Tenga has gone on to design the re-usable Tenga Flip Hole, Tenga 3D sleeves, and Tenga Eggs in a variety of textures. Unlike other penis sleeves, the Tenga Flip Hole can flip open for easy cleaning and features multiple textures within each masturbation sleeve. Additionally, the tightness of the Tenga Flip Hole can be altered by applying manual pressure to the exterior of the sleeve. Phthalate-free since their inception, Tenga sex toys are both body-safe and body-stimulating!