Reskins mining drones with ore harvesters from CnC, Red Alert, Tiberium Dawn for MD2R mod. Different harvesters are used for uranium / tiberium ore and other ones.
You can freely enable or disable this mod as it's only a cosmetic change, everything will work the same anyway. Graphics from C&C Harvesters mod by Daikael, but I also added depot/refinery shadow and harvesters ore tinting.