This tool comes with two blades, one for harder materials like aluminum and steel, and one for softer brass and plastic. Both are stored in the handle, and can be easy changed by pulling down the release collar at the end of the tool. Note that the blade for harder materials only cuts in a clockwise direction, whereas the soft cutting blade works in both directions. The blade for softer material is symmetrically ground.
The shaft extends by about 2 inches to help reach difficult to access burrs.
Instructions: Simply hold the blade against an edge as shown and pull with light pressure. When deburring straight edges with the blade for harder metal, start in the middle and pull to one corner. Then flip the piece and deburr to the other corner. Flipping the work is necessary since that blade only works in the clockwise direction.
Holes as small as 1/8" can be deburred.
Before and after pics:
Advice if you don’t have this tool: While a larger drill bit can be used to deburr holes, be wary of holding the bit with your hand, as it’s fairly easy to cut yourself with the flutes–especially on larger burrs. A better option is to use either this tool or a counter sink bit.