Traveling Tool Kit: Safe Edge Mill Files
Four sizes: 10, 8, 6, and 4 inch. I get the mill bastard cut because it's the cheapest, and I buy a box of each, so I won't be tempted to keep using a dull file instead of replacing it. I break the tang end off and grind the long edges and ends slightly rounded safe and smooth for truing up and beveling fret ends, and a variety of other tasks.