The system with rigid arches on the inside allows for a very intuitive attachment of the chain: starting from the upper part of the wheel downwards. The central aluminum rail is the heart of the automatic tensioning system: simply flip out the pedal integrated into the central rail and press it down with your foot to activate the tensioning process. When the vehicle starts moving, the chain is automatically guided around the tire. Welded steel rods with a special S-shape. External release system: just press the red buttons on the aluminum rail: the safety lock releases and the chain comes loose. Abrasion protection solution for lightweight metals (optional use). Practical and sturdy bag with integrated instructions, which can be used as a mat during assembly. Approval/Certificates/Conformity: Ö-Norm 5117, UNI 11313, TÜV.