This is an accessory or set of accessories for Gundam models.
Before now the only way to get the LEDs needed for such kits as the MG Qan[T] and 00 Raiser (both linked below) was to go through the parts department in Bandai Japan. Well, probably due to the enormous demand for these LEDs Bandai has opted to sell them in this great 2 unit set. This set is for the green LED used in the kits linked below. Each unit takes 2 LR41 watch batteries (sold separately).