Specifications Material: ABS Gear: 3 gears, 4 gears 3 gears adjustable height: 7/9/11CM 4 gears adjustable height: 6/9/11/12CM Appearance: rectangular Power supply method: No need Applicable parts: waist, hips, back Color: Blue, Purple, Green, Red, Pink Size: 38 x 25.5 x 11cm Function: Correction of the spine, improvement of hump / waist acid Package includes: 1 * lumbar relief 1 * English manual Features Posture correction: lumbar stretcher with soft rubber mat in the middle, padding of the impact force, better protection of the waist, preventive care of the lower back and posture help to correct and improve posture. Multi-level adjustments: The 3/4 gears can be adjusted, and the angle of the back arch can be adjusted as needed to meet the demands of the waist exercises. Made of high quality ABS plastic, environmentally friendly, robust and unbreakable, pressure-resistant. Easy to Use: Choose the level that suits your body and exercise your back in a healthy way to better get rid of the cause of back pain. The back extension device helps you to release your lumbar and back tension after a long day. Easy to carry: arc stretch for laying and sitting. Allow the waist to return to the normal 26 degree physiological curve. The backpack is light, easy to take with you when you travel or just enjoy it at home and in the office. The best gift to elders and friends. Product descriptions Instructions 1. Place the spinal correction plate on the bed or stable and set the appropriate tensile strength. 2. Place the spinal correction plate behind the buttocks with the back of the product facing towards the buttocks. 3. Lie down slowly. 4. Correct posture: sideways and armrest.