G-SAC is a combination of a disc and a bag filled with synthetic sand. Made of durable neoprene foam, fits snugly in the hand, does not absorb moisture and is resistant to dirt. It is soft and does not cause damage, thanks to these properties it can be used during home training. The "slam and catch" device is ideal for general development training, involving the deep muscles of the forearm. Exercises performed with G-SAC help to strengthen the stabilization of the whole body, improve concentration and motor coordination.