Gas spring, also known as gas strut or gas shocker, is a pneumatically pressurized tube designed to help open a door, lid or hatch. According to the strength of pull and push, capacity of the gas spring could be divided into several degree, such as 20N, 30N, 40N, 50N, 60N, 80N, 100N, 120N, 140N, 150N, 160N, 180N, 200N and 250N.