Oxfordís SHACKLE 14 D-Lock fulfils the three most important requirements of a quality D-Lock:Highly secure: it comfortably surpasses Sold Secureís ëGoldí standard by using a 14mm special hardened steel shackle and body mated to a simple but powerful locking mechanism with 3 replaceable keys.Easy to transport: Oxford devised a unique quick-release carry bracket which is both sturdy and super-easy to fit to a huge range of frame and seat post sizes.Reliable: a top quality pre-oiled locking mechanism is protected by a rubber over-moulded body to cope with the tough outdoor life that locks endure.The lock comes in 2 sizes; the 260mm length is a good compromise for general use