The Lelo Loki Wave 2 is a black prostate massager. It is a sex toy designed to stimulate the prostate and provide pleasure. To use it, it is recommended to apply water-based lubricant on the toy and anal area, then gently insert the prostate massager and turn it on to enjoy the different functions of vibration and movement. It is important to follow the manufacturer's instructions and clean the toy before and after each use.