Phono Cartridge Torque Driver.

Hex bit torque driver from the aircraft industry manufactured to ideal specification for phono cartridge mount hardware.

Note: This must be used with stainless-non magnetic screws. Mounting improperly can damage head shell or cartridge regardless of tools used. Experienced user required, common sense must prevail.

I've tested for more than three years, always improved sound, no issues, with:

Air Tight PC-1

Air Tight PC-1 Supreme

Koetsu Coralstone

Dynavector XV1s

Shure V15VxMR

Audio-Technica AT150MLX