Listing is for 1 (One) Service Caster 8" x 2" Polyurethane on Cast Iron Keyed Drive Wheel.
Bore Diameter: 18mm
Hub Length: 2-3/16"
Tread Durometer: 90-95 Shore (A)
Wheel comes standard with 2 set screws. One on the keyway and one 90 degrees from it.
(Picture shows 6" wheel)