1.Material Structure.Alloy steel,durable with a longer service life. 2.Handle Structure.free handle and double springs. 3.Concealed Cylinder Lid.Strong, Perfect in shape and easy to operate. 4.Surface Processing.PVD NM Technology, antiseptic,international standard. 5.Double Lock.Convenient and fashionable. 6.Reliable Performance.original electronic fittings. 7. LC Handset.Compatible T5557and M1 card,check lock info. 8.American standard.Five-latch cylinder,simple and durable. 9.Anti-inserted structure.Independent dynamo clutch design,sturdy and durable. 10.High-Quality Feel,Mechanical cylinder, Mifarel and T5557Card Module.