What is this and where do I get one?

Remove the right hand crank and bottom bracket cup.

Find a vice, hold the RHS of the bottom bracket shell onto the slightly open jaws of the vice.

Next, find a large punch and a large hammer.

Finally, hammer through the BB axle - should come off in 2 or 3 blows.

JOB DONE.

thanks, but no thanks, I very much doubt that would work with the internal cups of a shimano BB. At least not without ruining it and possibly the frame as well..