Heavy duty dolly has easy rolling swivel casters. Steel construction. Ship Wt. 22.0 lbs Poly Wheels Inside Diameter(in) 23.25 Drum Capacity: Poly Wheels 900 lbs. Heavy-duty welded steel drum dollies for maximum strength. 3"diameter casters welded inside the frame. Steel ball bearing casters for 360º maneuverability on almost any surface.