Product review (5 stars): Clears the jam; same as an allen wrench...
I found out about this tool when shopping for a new disposal.  I knew it was simply an allen wrench, so I searched online to find what size would work.  I couldn't find the info anywhere, so I'm posting it here.

This is the same as a 1/4" allen wrench.

If you already have allen wrenches, no need to buy this one.  If you don't, spend the six bucks on a nice balldriver allen wrench set that you can use for other jobs.