These are 3" Super Lite Wheels from Dubro. Black impact-absorbing foam construction pre-mounted on gray plastic 7 spoke rims. Rib tread design. Two 3" Super Lite Pre-mounted Wheels Wheel collars to hold them on the axle. May require reaming out the hole to mount on larger axle. Diameter: 3" OD Diameter: .178" axle hole Weight: 13.84 gr cmc 02/02/02 ir/kh &