H53, order number 116439-132, Three Piece Hot Water Circulator Pump, 1/2 h.p., 115/230V single phase, built in thermal overload protection, fitting in place of Bell & Gosset 60-13. These custom circulators feature the classic horizontal in-line design, engineered for durability and smooth operation. Designed for large flow applications. Impellers and motors are fine-tuned to meet the exact system requirements.