I am looking for (1) S/S 4"inlet and 4-1/2" outlet exhaust tip with the elec. actuator that when engaged just closes a butterfly in the tip which forced the exhaust around the internal muffler. I have 3 from my wrecked boat 312 Fastech and I'm looking for 1 to put in new 312 fastech. I have no idea who made these.. This is just a straight cut tip with a rubber flapper on the end. Any help on where to go would be great...

Hey Silent Lucidity-- this is Silent Lucidity. I have an answer for you.. They are from Teague ST450 muffler tips.. Hows that for an answer..
You rock, no you rock, no you rock.. No I rock....hahahahaha I kill myself.
Thanks Custom marine for the answer....... Found it and got it.
I just love thse things...

Hardin make two versions, one external and one internal muffler. Gaffrig also makes a switchable set.