This is a used but in excellent condition Marathon Digital (Mara) UCB2100 Control Board for the Bitmain Antminer S19 & S21. This board is the LTL version that does NOT have a dev fee so you get 100% of your share rewards (this does not include pool fees). The board comes loaded with the latest firmware from Mara. You can use the free Mara Tools software for bulk fleet management and firmware updates. Ships in original box and comes with 4 x fan adapters as seen in the photos.
