I have 2 AI hydra flex arm mounts that are like new . They were on my tank for a total of 2 days then I went to a T5 hybrid setup. I have have no need for them now. I live in Brooklyn wiould be willing to meet up within the 5 boroughs price is $100 for the pair.
Hydra 32 HD LED Reef Light - Black Body - Aqua Illumination
Have 2, each $350 plus shipping
Bought New Winter 2021, still have boxes, only used on my tank.