This replacement manifold is made for the AP-40 air pump, model 04540. It is a simple repair part when the original manifold is cracked, worn or missing, and it lets you keep the pump you already own in service.
Replacement manifold for the AP-40 air pump
Model 04540
Brand: Danner
Unplug the pump before servicing, and check that all connections are snug afterward so air does not leak, then restart it.