These are 2-3/4" Super Lite Wheels from Dubro.

Features

Black impact-absorbing foam construction pre-mounted on
gray plastic rims.
Rib tread design.

Includes

Two Wheels

Requires

Wheel collars to hold them on the axle.
May require reaming out the hole to mount on larger axle.

Specifications

Diameter: 2-3/4 OD
Diameter: .178" axle hole
Weight: 12.73 gr