Scope of delivery: 1 anti-theft hook + 2 keys, yellow, size: 15.5 x 11 cm, thickness: 1.2 cm, suitable for most tow hooks. Sturdy and durable: Made of high quality iron + aluminum alloy, rustproof, anti-corrosion, high temperature resistant, fine surface treatment, sturdy, practical and durable. Universal Compatibility: 11 locking positions can be adjusted and the size can be adjusted for different types of trailers. Available with 1-7/8 (48mm), 2 (51mm) and 2-5/16 (59mm) fittings. Easy to use: Simply attach the tow lock to the tow bar where the vehicles ball usually sits, then let it click into place and secure with the key. Deterrent: After installing the trailer hitch lock, the thief immediately loses interest. The bright yellow design provides a high level of warning and protection. Even in the dark, thieves know immediately that they have no chance of stealing the trailer