Usage: 1. It is forbidden to hit the air during use, and the rubber head must have a strong point. 2. Adjust the floor according to the purpose of use. 3. Place the handle of the bone adjustment massager on your palm. Place the rubber head on the part to be struck and apply downward force. Drag the black part of the position to the palm of your hand, and then drag it back and forth. Specification: Condition: 100% Brand New Item Type: Manual Spine Massager Material: stainless steel Six Level Strength: 50N, 100N, 150N, 200N, 250N, 300N Function: Massage the body, relieve joint pain, adjust bones. Package List: 1 x Bone Adjustment Massager 4 x function head 2 x Rubber Head 5 x Rubber Rings 1 x Storage Box 1 x English lesson