The SQ series are simply the best you can buy. You can expect a very long life from these pumps.
Quick disconnect union adapters for both suction and discharge ports. Inlet/outlet - 40 or 50 mm.
The older PM series had a rubber boot with 2 x hose clamps connecting the plumbing to the front/inlet of the pump, and a screwed on fitting at the outlet, where the later SQ series have a barrell union on the inlet & the outlet. This is the SQ Series. Download the brochure