The Marine Corps Military Occupational Specialty (MOS) 0842 is Field Artillery Radar Operator. Field artillery radar operators are responsible for:
Emplacement
Operation
Displace counterfire radar
Bore sighting the radar set antenna
Preparing the radar set common shelter for operation
Performing the radar set startup procedures
Gathering initialization data for the radar set
Loading the digital terrain map for the radar set
Operating the radar set in the hostile mode
Marines with the intended MOS of 0842 attend the Marine Artillery Radar Operator Course (MAROC). MAROC is 40 training days, or about 8 weeks.
You can buy a 5.5" red decal for the U.S.M.C. MOS 0842 Field Artillery Radar Operator. You can also buy a 5" military patch.