Rear Sprocket - 520 - 45 Tooth - 125mm Center Hole - Apollo Thunder 250 Dirt Bike 101290 Gaskets and fins on jug

Gaskets and fins on jug are also a help in determining the version you have

25 mounting bolt

Polaris          2007 - 2008    700 Dragon RMK

Exhaust mounting distance: 50mm

Rear Sprocket - 520 - 45 Tooth - 125mm Center Hole - Apollo Thunder 250 Dirt Bike 101290 Gaskets and fins on jugRear Sprocket 520 45T Apollo Thunder 250 Dirt Bike This rear sprocket is used on the Apollo Thunder 250. This sprocket has 45T and is compatible with the 520 chain ONLY. Sprocket details: #520 chain sprocket 45 teeth 125mm (4. 92 in) center hole 8. 5mm (0. 34 in) bolt holes Distance between bolt holes: 75mm (2. 95 in) center to center side by side Distance between bolt holes: 150mm (5. 9 in) center to center across Outside diameter: 233mm (9. 2 in)