It is quarter turn gear actuator, suit to be used on ball valves,butterfly valves plug valves etc,The housing made by precise casting, and the gear boxes have fresh pattern and nice appearanoe It transmitted by worm gear and worm, and the worm gear with self-locking.also by using tapered roller bearing, the gear box can be operated more flexibly and have higher efficience. Stem nut can be uni-body or separated just according to customers requirement.The mounting flange adapts to ISO 5211.