Vivosun 400 Watt dimmable ballast. Bought it off of Amazon, but I don't need anymore. Purchased it for $100. Sealed and unopened. Here is the description: https://www.amazon.ca/VIVOSUN-Dimmable-Electronic-Digital-Ballast/dp/B016POA4XM/ref=sr_1_6?keywords=400+watt+dimmable+ballast&qid=1583904877&sr=8-6 Thanks!