Wheel bearing assembly kit fits, and compatible with the 2 wheel Velke System tire size 9x3.5-4. One roller bearing replaces part numbers 77410031 and VKXRLBRG. And the two bearing retainers replace part numbers 77410030 and VKXBRGRTNR. Bearings will need to be greased. Includes washer kit, 4 washer 7/8" ID and 2 washers 1" ID