I have some used National ceramic sockets that fit the 4-125A, 4-400A, 3-500Z, etc tubes $10 each plus shipping. If you buy four or more, I'll pay for shipping. EIMAC 4CX300A ceramic tubes, qty 3, with one EIMAC socket, $50 plus shipping. 815 tubes, will check them, $10 plus shipping Pictures available 73 Kees K5BCQ