Kangoo Jumps KJ XR3 X-Rebound Exercise Jump Boots are a type of suspension trainer that can be used for home, semi-commercial, and commercial use. They are designed to work the legs and full body and come in black with gray and orange accents. The boots are made of plastic and are a large size jump boots. They can be used both indoors and outdoors for gym and training activities. These boots are in excellent used condition. These are unisex and really fun.