The installation position is various,comprises locking bar unit that onto round tubing,Anti-theft such as handlebars Easy to install,no instruction. Fits all half helmet, full- helmet, and crash helmet.This cable lock can be perfectly used to your helmet, bags, jacket, shopping bags, and more. Fits for 20-26mm handlebar tubing, engine guards, rear bumper, tubesor any long section of straight tube. Fits all motorcycles, street bikes, , electric vehicles and bicycles. Made of aluminum material, which provides security and toughness, waterproof, rust and corrosion resistant. Size:7.6cm/2.99inch x 6.5cm/2.56inch x 2.3cm/0.91inch. color:Black Material:Aluminum Package Contents: 1 x bicycle locks set 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.