What is the purpose of these holes on my wire stripper?
PLIERS
Used as pliers.
Stripper
80 - 22/20
Strip 22-20 AWG (.8 mm) wire.
1.0 - 18
Strip 18 AWG (1.0 mm) wire.
1.3 - 16
Strip 16 AWG (1.3 mm) wire.
1.6 - 14
Strip 14 AWG (1.6 mm) wire.
2.0 - 12
Strip 12 AWG (2.0 mm) wire.
1.6 - 10
Strip 10 AWG (2.6 mm) wire.
CUT
Used to cut wires and cables.
LOOP
The loop hole is used to bend hooks in wires, so that the wire can be attached to screw terminals.  Place the tip of a stripped wire into the hole, and bend the wire around the body of the tool.
Screw/Bolt Shearing Holes
The other holes in the middle of the body, are screw/bolt shearing holes. They are used to cut small screws/bolts to length. To use them, simply thread the screw/bolt into the proper sized hole to the desired length, then squeeze the handles together. The screw/bolt will be trimmed, without damaging the threads.
CRIMP
INSUL AND NON-INSUL
This means that you can crimp insulated and non-insulated crimp terminals
16 - 10
This means the tool can crimp insulated and non-insulated 16-10 gauge crimp terminals. The colors below represent the color of the insulated crimp terminals, for quick reference.

Blue = 16-14 Gauge

Yellow = 12-10 Gauge


22-18
This means the tool can crimp insulated and non-insulated 22-18 gauge crimp terminals. The colors below represent the color of the insulated crimp terminals, for quick reference.

Red = 22-18 Gauge


INSULATION ONLY 7 - 8MM AUTO
This means the tool can crimp insulated 7-8mm auto ignition wires (spark plug wires).