Big Bottle Tetrode.
Electro-Harmonix tubes are all new designs and are of excellent quality. Designed to the exacting specifications of the Phillips 6CA7, this classic tetrode returns to life in a big bottle design. The 6CA7EH is built to withstand today's high-gain amps while still retaining the detailed tone and component integrity of the original. A direct replacement, with military reliability, for any EL34.