Try looking up the model number or serial number if you can find one. That should come right up.
I just installed it externally. Workin' like a champ! The hardest part was coming up with fittings to match the inlet and outlet on the pump and the drain on the fish tank. I sure wish they made pumps that would accept standard PVC fittings. I get sick of buying weird sized, expensive vinyl tubing and hose clamps just so I can step the outlets up or down into standard plumbing.
I only buy pumps that accept standard PVC fittings!