For the asking price, you get what you paid for. The air cyclinders and valve both leak air. The "O" rings in the cyclinders are the incorrect ID. This also applies to the "O" ring in the control valve. The machning of the retract assembly allowed lateral and linear motion of the strut assembly. This provided a large tracking error to develope during takeoff and landing. They sure look pretty but I ennded up replacing them with "Sierra" retracts.