These are 2" Super Lite Wheels from Dubro.

Features

Black impact absorbing foam construction pre-mounted.
Gray plastic eight spoke rims.
Seven rib tread design.

Includes

Two 2" Super Lite Pre-mounted Wheels

Requires

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

Specifications

Diameter: 50.8mm (2")
Axle Diameter: 3.5mm (.141")
Width: 17.4mm (.686")
Weight: 5.22 grams each wheel