Republic HRC1452 two-stage side channel blower with IE3 premium efficiency 30.8 HP, 50/60 Hz, 3-phase, wide-range voltage, TEFC (IP54) motor. Standard features include heavy duty aluminum construction, cool-running outboard bearings for long life, integrated inlet and discharge silencers for quiet operation, 4" NPT inlet and discharge connections, and a cUL, UL, and CE listed motor with class F insulation. An inlet filter and relief valve are strongly recommended and sold separately. Fully assembled packages with inlet filter, relief valve, gauge, and even sound enclosures are also available.