http://www.sbrammunition.com/lasermatch.html
These guys make cheap tracers, but I would advise staying away from them. The first batch I got had an 80% failure rate. I e-mailed them about it and they were very nice. They said the guy running the machine the day mine were made got a little excessive with his lubrication and spoiled the lot. So they replaced my order with ammo from a different lot...
These were not much better. The traces were barely visible even in low light, and many rounds just produced a huge muzzle-flash without any visible trace.
I like to use tracers for point-shooting drills and entertainment in general, but I will not be ordering any from these guys again. You get what you pay for, I guess...