6" steel with "centered" hub, perfect for a mini bike or go kart front wheel. Comes with 5/8" id bearings installed. Wheel has 4 Bolts on a 90mm (3.54") Bolt Circle Hub has two 5/8" ID Ball Bearings, with 2-1/2" Bore Length Overall width 3-1/4" Bead width, 2-3/4", fits most 6" Tires Two piece Rim for easy tire mounting