Puma Belt-Drive Stationary Vertical Air Compressor - 60-Gallon Vertical, 4.5 HP, 18 CFM, Model# PK6560VS Durable cast iron oil-lubricated pump for long life and no heat transfer between cylinders Copper finned inter- and after-coolers provide good heat dissipation and less moisture Ball bearings on each side of crankshaft for smooth running and durability Heavy-duty paper element filters keep cylinder heads clean Durable metal belt guard won&#39;t break