PEQ-2, PAQ-4, PAS-13, PRC-119 (SINCGARS), PRC-77
Ever wonder why some military hardware has these funny names?
It's a electronics designation system designed by the Army/Navy during WWII called JETDS (Joint Electronics Type Designation System).
Each JETDS device has a three letter code designating its use, prefixed with A/N and ending with the series/model number. Some examples:
Army/Navy, Human Portable, Invisible Light, Detecting - Search, Model 13
Army/Navy, Human Portable, Laser, Combination Purposes, Model 2
Army/Navy, Ground Transportable, Visual/Visible Light, Detecting - Search, Model 5
Army/Navy, Human Portable, Radio, Communications (two way), Model 77
Intuitive, right? ;-)
Full documentation is here: