what about a marine store? You should be able to hold them in your hand and get a good idea for yourself...
Although, most if not all I've seen from a marine shop are plastic and very non-flashy.
I had one on my 550, and it was VERY long... threads were long, and then it had a barbed end for the hose to fit on.. all and all it ended up to be over 3" maybe even 4" long. But it was very plastic and dull looking...