Standard AR- M16 Extractor with small flat machined to for STG 1928
2010-2018 pattern: This has a .017 step in the extractor for the parkerized pattern STG1928 bolts.
The new Nickel Boron plated bolts use the standard Universal pattern extractors with the .01 step. These are the same as the U45 and U9 extractors.
Includes custom heavy extractor spring and mounting pin