"My second AR" Olympic Arms "M4A2 clone" retro-modded

SHOW AND TELL: "My second AR" Olympic Arms Multi Cal 2009 "M4A2 clone" retro-modded.
Not mentioned : The bolt-catch-release lever has an extended catch pad. Gas rings have been replaced.
Link to video on the manual : https://rumble.com/v4jmyyu-book-review-olympic-arms-inc.-owners-manual-for-ar15-car15..html