Brand Forceball Model SPT-ALC Quantity 1 Color Yellow + green + black Material Plastic + silicone Functions Equivalent to 50 different dumbbells about 14kg at 8000rpm; With PC cover and silicone anti-slip pad great hand feeling; With colorful light during moving; Perfect exercise gadget for sports such as golf tennis squash cricket badminton baseball bowling basket-ball motocross and mountain climbing etc.; Also great for those need often using wrist like playing computer and various instruments writing and drawing & painting etc.; Increases the strength and flexbility of fingers wrist hands forearm biceps triceps ligament and shoulder; Rehabilitates sore muscles and joints Best use Multisports Packing List 1 x Force ball 1 x Wrist strap 1 x Starting rope (40cm) 1 x English user manual