This is the Dubro Treaded Lightweight 6" Diameter Wheel.
FEATURES: TL Series Foam Interior yet has a Tough and Rugged Exterior Skin 8-Spoked Gray Plastic Wheel Shock Absorbing 3/16" (5mm) Axle Diameter and Can be Drilled to 1/4" (6mm) maximum
SPECS: Tire Diameter: 6" (152mm) Tire Width: 1.5" (38mm)
INCLUDES: One Tread Lite 6" Wheel