Secure Valve Lock Ideal for preventing valve tampering. Prevents air leakage from the valve. Compatible valves: English valve Installation tools: 10mm spanner (box wrench) etc. ① Inflate the tire sufficiently. ② Tighten the top nut firmly with your fingers. ③ Screw the valve lock onto the end of the valve with your fingers. If it's difficult to secure, apply water to the O-ring of the valve lock to fix it. ＊ Carefully secure the valve lock horizontally with a 10mm spanner (box wrench) etc. ④ Finally, check that the valve lock cannot be loosened by hand and that there is no gap between it and the top nut. Over-tightening can cause air leaks. ＊ If there is an air leak, loosen the valve lock once and try again. ＊ Depending on the valve shape, some valve locks may not be installable (the valve may rotate when securing), so please check with your retailer. Size: 20 x 10 x 10mm Weight: 5g Quantity: 2 pieces Compatible valve: English valve Shipped in simple packaging. Please purchase only if you understand.