I dont need one, I don't think I mentioned needing one, I have been told that of I use two 3000TL LVM ES's that one needs to be neutral bonded and the other not bonded, I have been told both units need to he bonded, been told neither can be bonded, you name it I have been told it so as far as I can tell growatt are of no use to anyone, even the "technical support" at responses are ya i think it should work or I'll dont see why not etc. Can't get a straight answer from anyone at the growatt dealer, signature solar has been of no use to me, not even sure why they sell something they know nothing about, gonna get someone killed with the answers they give