These are 2-1/2" Diamond Lite Wheels from Dubro. FEATURES: Black impact absorbing foam construction pre-mounted. Gray plastic eight spoke rims. Eight Rib tread design. INCLUDES: Two 2-1/2" Diamond Lite Pre-mounted Wheels REQUIRES: Wheel collars to hold them on the axle. May require reaming out the hole to mount on larger axle. SPECS: Diameter: 63.5mm (2-1/2") O.D. Axle diameter: 4.4mm (.175") Overall width: 20mm (.788") jm 10/02/02 ir/kh