Item Description: KEF-based Transmission-Line Loudspeakers Bsed on design by A.G. Bailey Published in Wireless World May 1972 Drive units are: B139, B110 and T27 with DN12 crossover Photographs and Information supplied by Roland Collaro 23/02/2004 - Email rolandc@iprimus.com.au enquiries@hifiloudspeakers.info