Made of high quality iron and aluminum alloy, with special coating, , rustproof and weatherproof. The U-shape lock can resist picking, prying and drilling. Works with most caravans and trailers with 50mm tow balls as standard. The Lock fits 1-7 or 8Inch, 2Inch, 2-5 or 16Inch couplers and ratchet is adjustable with 10 locking positions. It is easy and quick to install and remove,and bright yellow color can provide high visibility. Each lock is supplied with 2 keys. Guards against theft of caravans and trailers. Note: Installation guide not included, we strongly recommend you professional installation. Please check as much as possible to make sure the item is what you need. Tips:The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Colour:As Shown Material:aluminum alloy Package Contents: 1 x Trailer Lock Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.