JBJ 28G NanoCube Replacement LED 3 Watt Dawn/Dusk Internal Ballast (for MT-601) JBJ 28 Gallon Nano Cube Advanced Aquarium with LED Lighting (MT-601) Replacement LED 3 Watt Dawn/Dusk Internal Ballast. Part #15 on the exploded view diagram in the JBJ 28 Gallon Nano Cube Advanced Aquarium Manual NOTE: This is the new version. The old version was gray/white, and the dimensions are somewhat different. This is the only version now available.