I'm an electronics technician by trade and I wanted to make a headphone amplifier that'd fit in a mint tin. I needed holes for sound-in and sound-out and tried using a drill. Even carefully starting with a center punch, small drills and going up in increments at low torque would shred the surrounding area. This hand punch - if you face it the right way - leaves clean holes for you to mount headphone jacks on. The instruction manual is a great touch, since it shows an exploded view of every part in case the punch needs service, as well as tips on maintenance.