The pump Trracer or the later semi auto Trracer?
Pump is PMI,Maverick, ACI threading. Some options but not a lot.
Semi Trracer is Spyder threaded. The semi is a very cheap plastic bodied mass market deal. If you're serious about the game best avoided since other metal bodied options are so easily gotten for the same or slightly more $.
I just thought I'd take a quick peek and then the world went all yellow.....