These hubs are 3/4" ID 3/16" keyway with a 4 on 4 bolt pattern.. When ordering these hubs allow 10 to 14 days because they are all built when ordered at this time. The hubs are best held on by a bolt in the end of the axle and a shaft lock behind the hub orshaftlocks on both sides. You can add a 1 1/4" brak adapter for $10 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 $25.00 each or $35.00 each for the hub with the brake adapter.