20 Ton Pneumatic Air Hydraulic Bottle Jack with Manual Hand Pump Heavy Duty Auto Truck Travel W1239124011SIMPLE OPERATION Clamp one end of the handle bayonet to the oil return valve and then tighten clockwise; Connect the air pipe port to the air compressor interface, and then press the switch to raise, otherwise, it will stop; After it works, rotate the oil return valve pile anticlockwise and slowly, and it will drop automatically Versatile and Adjustable: With a minimum height of 10. 2" (260 mm) and a maximum height of 20. 1" (510 mm), this jack