Rear Hub with Studs for 150cc Trailmaster & Hammerhead Go Karts Part # 8.010.089 Rear hub used on many Chinese 150cc/ 250cc/300 go-karts (TrailMaster, Hammerhead, Carter, American Sportworks). 10mm nuts not included. Studs spacing is 4/136mm or 5.36" across (measure diagonally). Center splines are 25mm **Works with 24 spline axle**