Impact extension info needed

[Tinkerer2]

I saw a mechanic use what I think was a snap on extension. It was about 6 inches long and had a blue sleeve over it so that you could use the sleeve as a hand hold. What are these called?

 

[dnschmidt]

ICON makes these as well: https://www.harborfreight.com/10-in-12-in-drive-speed-collar-impact-extension-bar-63908.html