Akron Brass GP [3430] Manual Monitor. The GP Manual Monitor is one of the most cost effective, highest performing firefighting monitors found worldwide. This monitor's rugged, lightweight design was engineered using some of the world’s most advanced computer aided design and testing technology, resulting in performance seen by no other 1000 gpm (3800 lpm) monitor today. Once you grab the dual handled controls, you will know you are using the most highly maneuverable, easiest operating, most versatile fire service monitor in the world.