These are Low Bounce Treaded Wheels by Du-Bro.
FEATURES: Shock Absorbing
Fits inside most Wheels Pants and Retracts
Grey Eight Spoke Hub Design
INCLUDES: Two Wheels
REQUIRES: Nothing
SPECS: Diameter: 57mm (2.25")
Hub Diameter: 4mm (.15625")
Width: 20.0mm (.775")
COMMENTS: None