File:Bulls Iberville Red Stick Kneeling.JPG - Wikimedia Commons
HILMAN ROLLERS, 4 ton Load Capacity, 5 in Deck Ht, Bull Dolly Kit - 60TR64|KBSP-4P - Grainger
HILMAN ROLLERS, 72 ton Load Capacity, 7 55/64 in Deck Ht, Bull Dolly Kit - 60TR69|RS-BSP-72P - Grainger
From the Vault: Bulls on the Beach - PBR Blog
Type A Small Diamond Bull's Eye Universal Wheel Steel Ball Wheel Universal Ball Car Steering Wheel Material Tool Ball Wheel - Window Rollers - AliExpress