Pretty sure they have a patent on it. I remember hearing years ago they had patents on other interesting stuff.
Wouldn't see other companies trying it for a while to be honest. You need parts that are made of high quality material, tight tolerances, etc.
Originally Posted by kingcatnip
Wouldnt having a patent for the spool design in general be like having a patent for the combustion engine?
Well, on another note, didn't Smart Parts have the patent on the microswitch for paintball?