Armstrong Astro 2 Series Astro 250CI, 115 V, 1PH, 60 Hz (110223-307) It is designed with no mechanical seals or couplers to replace Efficient/Quiet Operation Universal Flange to Flange Intended for circulating water or ethylene glycol solutions in closed hydronic or solar heating A hydronic circulator that conserves energy and eliminates maintenance systems No lubrication is required. Manufacturer Part Number 110223-307