The ATS is an example of extreme technological advancement in gear, designed by O.N.I to highlight enemies whilst scanning the surrounding area for technology and reviving other Spartans. This variant however used by the UNSC's medic squads are designed to locate any gravely injured Spartans or ODST , and quickly inject BioFoam via needle for an emergency.... ( Note: ODST call these devices Toasty Buns)