[2021] Delta sight for all pistols?

Originally posted by VIC7ORツ: it would be cool if that was a feature as there is a delta sight on the "mp9" and its not too broken so if it could be on all pistols that would be cool. And in a game where there are literally moving holograms, I dont think putting a sight on a pistol would be that hard.

I feel like a smooth brain for asking, but what exactly is a Delta Sight?