16" Dia. X 6" Flat Free Tires With Deep Treads For Traction On Damp Grass And Muddy Terrain, Solid Polyurethane Foam Filled Will Never Go Flat, Steel Hub Accepts 3/4" Steel Axle, Complete With Erie Standard Roller Bearings And 1/4" Grease Nipple, Wide, Deep Tread Won'T Sink Into Soft Surfaces, Fits All Current Erie Contractor Models - 1035'S, 1038'S, 1015'S And Brick Carts