In my IMPD July 2011 mag I noticed an add by E-Z RED

Wrench connection - Metric and Imperial (standard)

These are like top hats - the inside of the hat is square drive female
set up for your socket driver or breaker bar. The outside of the hat
is a hex drive that fits into a box end or straight wrench.
The rim of the hat contains two magnets that help keep the wrenches
attached.

So a box end attaches to the work and is extended by a breaker bar or
socket wrench.

http://www.ezred.com

Martin