Features： 1、Ergonomic: Fit the curve of human body traction spine curve design, closely fit the spine, is conducive to upright sitting. 2、Back Stretch: It is conducive to back stretching, improved mobility with the spine deck, designed to help you enjoy your life. 3、Adjustable Settings: You can choose the most suitable and comfortable height to stretch your back and relieve stress. The higher the height you set, the stronger the stretching force you can get. 4、Multiple Auxiliary Massages: For targeted spine decompression, which exert pressure on specific areas of your back to release tension and enhance blood circulation. 5、PP Polyurethane: Made of safe and environmentally pp polyurethane, the back cracking device is resilient, sturdy and can be used for a long time. Specification： Item Type: Back Massager Board Material: PP Package List： 1 x Back Massager Board