I have an DX Engineering Maxi-Core High power transmission line balun, 1:1, info for this particular model can be found on the DX engineering website:
Used for a few weeks, still have original receipts, doesn't work in my hoa situation, so my loss is your gain! Selling for $100 o.b.o. +s/h.
Copper tubing & coax shown in pic are not included :)