This is a pair of AER Mk I full range drivers. Both drivers need re-coning, which will, in the US, run $600-800 (depending on currency fluctuations) and is available from the importer, Tonian Labs.
I'm thinking $250, but will consider offers; these are probably the least colored of the Lowther style drivers. I ran them for years in a pair of Lamhorn 1.8 cabinets.
Local pick-up warmly welcomed, but I will ship.