Security Chain Company Z6 SZ 143 chains - never used. $50 Selling my Tesla so no longer needed. A must have in your car if you drive in the mountains just in case. These have never been used. Engineering for cars, pickups and SUVs that, by design, restrict or limit the use of tire chains due to low clearance. Meets Class S" Clearance Requirements. Requires on 6.3 mm (1/4 inch) clearance. Quick Easy Installation Better traction and durability than traditional link chains or ladder style cable chains. Enhances electronically monitored traction control systems and anti-lock brakes Includes: Rubber tighteners, plastic gloves, and illustrated installation instructions.