Pentax CM40 Range of Centrifugal Pumps, Pentax CM40-125A, CM40-125B, CM40-125C, CM40-160A, CM40-160B, CM40-200A, CM40-200B, CM40-250A and CM40-250B Pumps. Centrifugal Single Stage Monobloc Pumps Surface Mounted Pumps. Monobloc horizontal centrifugal pumps, constructed to EN 733 standards; widely used in water supplies, pressurisation and fire-fighting systems, cooling, heating, irrigation, industrial and agricultural applications; standard supply with counter-flange.