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.