Controllable gas spring, also known as lockable gas spring, angle-adjustable gas spring, controls the stroke by opening and closing the valve, so that the stroke can be stopped at any position, and is mostly used for tables, beds, desks, chairs, paint lamps and other angles, Where the height needs to be adjusted. According to the locking force, it can be divided into elastic locking and rigid locking, and rigid locking can be divided into compression locking and tension locking according to the different locking directions.