While most Scrin were satisfied with merely keeping their harvesters out of harm's way, Reaper-17's aggressive tactics often do the contrary. To minimize losses, Reaper-17 had its harvesters equipped with a Tripod's energy field generator. Unlike most shielded units, the Shielded Harvester has its energy generator installed by default, without any need to upgrade it. These variants were first deployed in China during the Third Tiberium War.
A harvester comes free of charge with every new refinery. It automatically starts searching for available Tiberium fields and collecting crystals before returning back to the refinery to have them processed. When lost, warp spheres and warp chasms can build a new replacement. The shield can absorb a single EMP blast as well.
They are otherwise unable to defend themselves, and like other Scrin harvesters, they cannot crush infantry.