WHAT DOES FRT-15L3 MEAN?

I've attempted various distinctive forced reset triggers, starting up with rare breeds unique. When the ATF commenced knocking on doorways while, I disassembled it, grinded it up and tossed it during the trash as I didn't want any drama from the legally purchased trigger. Anyhow, these triggers are awesome. The FRT-L3 is the best I've applied up to