There are times when you want to debur the backside of a hole, but you don’t have enough room to use a regular deburring tool—think for example of the inside of a tube
that you’ve drilled a hole in. The Burraway is a spring-loaded tool that deburs both sides of the hole. You can see a video of how it works here. Search for “two-way deburring tool” on eBay and you can find Burraway as well as generic knockoffs, new and used. You probably won’t use it often, but you’ll be glad you have one when you need it!