Durable and time tested. Stands up to the the most gruelling conditions and provide years of reliable service. Ultimate vacuum – 15 microns. ( 3 & 6Cfm )Ultimate vacuum – 12 microns. ( 10Cfm ) Slide switch recessed for protection.Vapour discharge / oil fill port, easily removable. Contains internal check valve to prevent escape of liquid oil. Cooling fins to keep temperature cooler during long operations. A Quality product from Mastercool, USA.