Hex hubs for the SLW Series wheels, set come with 2 hubs enough for 2 wheels.Track width values below were taken from outside of wheelAxial Measurements225 = 8.55, 350 = 8.80, 475 = 8.92, 600 = 9.05, 725 = 9.17With 350's we get1.000 wheel to wheel Inside measurement = 6.821.350 wheel to wheel Inside measurement = 6.12Berg225 = 9.50, 350 = 9.750, 475 = 9.875, 600 = 10.00, 725 = 10.121.000 wheel to wheel Inside measurement = 7.761.350 wheel to wheel Inside measurement = 7.06HPI Crawler King225 = 9.56, 350 = 9.81, 475 = 9.93, 600 = 10.06, 725 = 10.181.000 wheel to wheel Inside measurement = 7.821.350 wheel to wheel Inside measurement = 7.12
