After George posted his Hilbre thread, it reminded me of another broadhead I have with a plastic ferrule. This one is 3" long and 1.25" wide, and has a marking on the back of the ferrule of an arrow through a square.

Threads like this are useless without a pic, so...

Arrowmate 4-bld, late 1950's

... that was easy  :p
They come in all colors of the rainbow too!

Falk, I knew you would know this one.    

They appear to be of the same quality as the Hilbre...and probably not worthy of hunting anything bigger than a groundhog, huh?  

well, I can't tell on their durability, but I guess you are better of using a "real" broadhead on bigger game.
There is an Arrowmate 3-bld as well. Looks like a Woodsman on first sight.

For some reason I always had a special interest in these so called composite heads. They always appealed to me, not all in the same way, but I have collected some types. Hunting with them is a complete different story ...