These hubs are 3/4" ID 3/16" keyway with a 4 on 4 bolt pattern. they also have 4 gussets on the back side for added strength,there are 2 set screws. When ordering these hubs allow 10 to 14 days  because they are all built when ordered at this time. This hub on a Peerless 930 put my tires at 37 1/2" wide. but I use 7x8 wheels with 8x8 wheels you can get right to 38" the hubs are best held on by a bolt in the end of the axle and a shaft lock behind the hub. You can add a 1 1/4" brak adapter for $8 it is welded to a hub so you can use a 1 1/4" disc mount from a cart. click on the pull down box for the option. The price for these hubs are $34.50 each or $42.50 each for the hub with the brake adapter.