Black, silicone butt plug with 2 heavy balls inside create a unique sensation. The 2 balls will knock and shake once you inserted. Key Features:- Length: 10 cm- Diameter: 2.2 cm and 2.6 cm- Color: Black- Material: smooth silicone Note: Use only with water based lubricant! Contact with oils and creams (sunscreen, edible oil, lip balm, etc.) may cause irreversible damage to the control unit and the entire toy. How to clean: Carefully clean the toy before first use and after each use with warm water and a mild soap. The cleaner is especially suited for cleaning erotic toys