High Security D-Lock U-locks are the most widely used bicycle security solution. The new High Security U-lock from Yale are both convenient, strong and secure. Constructed from ultra hardened steel, and with double point locking technology, they are designed to resist all forms of attack. The High Security U-Lock is independently tested achieving a Sold Secure Gold rating and carry a five year guarantee. Featuring new pick, pull and bump resistant mechanisms and a longer shackle allowing wider and easier locking options when out on a ride. Usability features include a double rubber coating to protect paint and internals and 4 laser cut keys (including 1 with micro-light). For peace of mind, protect your bike with Yale.