Rear Sprocket - 520 - 45 Tooth - 125mm Center Hole - Apollo Thunder 250 Dirt Bike 420H x 70 Large circular piece on top

Large circular piece on top left

5/8 inch Bore

Just remove the weather resistant boot

2 prong flasher

Rear Sprocket - 520 - 45 Tooth - 125mm Center Hole - Apollo Thunder 250 Dirt Bike 420H x 70 Large circular piece on topRear 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)