Using a drill bit diameter gauge, I can put the 12/2 wire through a 5/16" hole. Nothing smaller, even by 1/64" works. Obviously, if you are running this through thicker material (2x4 studs), your hole better be larger than the 5/16" bare minimum.
Cost effective, safe-to-run-in-walls method for connecting my Dolby Atmos 11.1 Receiver to my Monoprice Amber speakers. I don't know why people complain about its stiffness as I had little problem running it along a wall under the 3/4" baseboard covering the carpet edges. I bent it around 90 degree° corners with a bit of effort. I also ran it through 1/2" holes drilled in the bottom of studs (covered by baseboard trim) where a tile floor prevented me from tucking it under the baseboard. Certainly not convenient, but very doable with a bit of patience.
Worked well for constructing wires (with Monoprice banana plugs) between the AV/R and the wall-plate. However, it required a bit of precision/effort to force the 12AWG into the plugs, but very doable (probably about 2 minutes per plug with the right tools and practice).
I also designed a 3D-printable 8-wire clip (Thingiverse Thing ID: 3059854) Monoprice also sells clips that would probably work well. It was even printed on a Monoprice Architect 3D printer.
Bought this cable b/c it was 12-gauge and black. Was intending on connecting the subwoofers in my home theater to their amps. Didn't work out as planned. As this cable is plenum-rated, that means it's legal to run inside walls and plenums. That's good if that's your intended usage. But be warned; the jacket on this wire is stiff. VERY stiff. If you're familiar with Romex cable, that's exactly how this wire bends...or not.
This wire is so stiff that it won't lay flat on the floor when trying to run it behind furniture, under rugs, etc. I had to return it.
Depending on your intended usage this wire may or may not work out for you.