Usually the boxes of screws come with the bottom, more silver bit. But today’s box had the duller grey, bit with a green lap band. No idea if one is better than the other or not.
Edit: Thanks to @0x0@infosec.pub for the wiki article!
Bits like that are used for impact drivers
That is where I was leaning too. It was the only bit I used today, and it performed well enough. I did strip one screw, but that was my fault, and it backed out just fine.