Specification: Chain Number: 420; Pitch: 1/2 "; Roller width: 1/4"; Drum diameter: 5/16 "; Chain wheel thickness: 0.227". The circuit breaker is suitable for a 420-530 inch (approximately 114.4-143.4 cm) chain, with a total length of 59 inches (approximately 132 cm) Size: 420 motorcycle chain, 132 links including 66 internal links and 66 external links, can be added or removed according to your needs, with installation tools included. Suitable for 50 70 90 110 125cc SSR TaoTao Coolster Apollo Baja Kazuma Chinese ATV 4-Wheel Four Pit Off Road Vehicle 212cc Karting Mini Bicycle Power Sports Parts Packing list: 1 piece of 420 mini bicycle motorcycle chains, 1 chain derailleur, and 2 chain connectors. Please check if the chain size of your motorcycle is correct before purchasing