What's it for?
It's also used as impact driver, to free up the screw should it start to deform . . .
so you can put a 13mm wrench on one end and crank down with more torque than your hand could

Loosening and tightening screws with a #2 phillips head.
Loosening and tightening screws with a #2 phillips head.
Surely not!![]()
Just put an impact wrench on itThis design seems inferior since the user cannot press down on the end of the handle while employing the wrench to turn the driver.
A "homeowner's" brand, so just gimmicky I'd guess...
Just put an impact wrench on itProblem solved!
And then you have a new problem - twisted off screws...

Aha, well found! Teken and jjarrell4 have it:
"The end hexagon hammer plate will sustain impact from a hammer and can also be used in conjunction with a spanner or ratchet"
What a pointless innovation
I was thinking along the same lines as Mickey O's second post, that someone was going to say 'what, you've never seen the fitting on a ... before??'