Dumb question about LMT AR serial #

[ShakyJ]

I just bought an LMT AR lower (defender 2000) that I am in the process of registering for a SBR. Here is my dumb question: It reads "SER. LMT #####" Is LMT part of the serial number? Or, is the serial number just the 5 actual numbers? I appreciate any help on this subject.

 

[Killermonkey21]

I'm pretty sure that everything past "Ser #:" is part of the serial number. On my M&P the serial is MPSXXXXX, and the whole thing is the serial number. That would be my best guess.