Kryptonite Keeper Chain Lock This robust chain lock has links with a thickness of 7 mm and is relatively light at 1.67 kg. This lock is equipped with a combination lock. The nylon cover is durable and weatherproof and ensures that the frame of your bike is not damaged. Specifications: Color: blue Chain material: steel Cover material: nylon Length: 90 cm Link thickness: 7 mm Weight: 1.67 kg Warranty: lifetime