It’s the price per plate
The level IV Ceramic plate is NIJ Level 4 tested by the US National Testing System to stop 7.62mm armor piecing (30.06ap) rifle bullet traveling at 2880 ft/s.
Guard Dog Body Armor does not state where the Guard Dog Body Armor Level IV Ceramic Plates are produced. I recommend contacting the manufacturer for that information.
The OPMOD plate has an anti-spall cover that is kinda rubbery. It is slightly heavier than the standard plate. Couldn't say if you need a trauma pad but it's a meaty plate and your carrier should have a little material in between. I'm not running a pad but YMMV.
"Sold Individually, if you would like to order a set, simply select QTY (2)."
The Guard Dog Body Armor Level IV is tested to NIJ Level IV standards. The Level IV is an imported item.
The Guard Dog Body Armor Level IV Ceramic Plate is Level IV, multi-hit, and NIJ .06 tested. NIJ Level 4 tested by the US National Testing System to stop 7.62mm armor piecing (30.06ap) rifle bullet traveling at 2880 ft/s. Guard Dog Body Armor’s Level IV ceramic 10”x12” plates are made from a combination of Alumina and PE meeting the NIJ standard 0101.06 Level IV standards tested by United States NTS.