This acorn nut set is designed for use with 7mm engine head studs on pit bikes, dirt bikes, ATVs, and with 125cc to 140cc engines.The set includes acorn nuts that fit securely over the studs to protect threads and provide a finished look.Made to standard specifications, these nuts are compatible with common small engine configurations found in off-road vehicles.The hardware is intended for straightforward installation and performance in standard operating conditions. This is a non-OEM replacement.Any mention of brand names is strictly for compatibility clarification.