Useful. The vitality fitness device can not only keep fit, but also perspire and lose weight. It is the simplest, convenient and fast perspiration exercise machine in the world. It uses an innovative single-screw vibration fat-reducing and ultra-miniature noise motor to stimulate fat accumulation parts through transmission vibration, break the fat into small pieces and get rid of the fat layer, thus achieving the purpose of assisting weight loss. It is the safest non-destructive slimming and shaping product at present.