Snow chains equipped with automatic tensioning and patented quick external release. TECHNICAL FEATURES: 9 mm internal footprint; self-tensioning system; external quick release system (the snow chain can be removed by pulling the special device); patented micro-adjustment system for perfect chain tension; patented rim protection system alloy. Approvals / Certifications / Conformity: Ö-Norm 5117, UNI 11313, TÜV. Not suitable for off-road routes.