Ceramic 4Pin Tube Socket 2A3 300B 5U4G 811 PX4 274A U4A 1.Min. Order: 100pcs 2.FOB Price: US $1-2/ Piece Ceramic Tube Socket 2A3 300B 45 5U4G 811 PX4 274A U4A Base 4PinFor 300B,2A3,811,45,50,71A,83,5Z3,572B,5U4G,6B4G,274A,866,PX4.....Screw Mounting Distance: 45mmHole size: less than 42mm Ceramic Tube Socket 2A3 300B 45 5U4G 811 PX4 274A U4A Base 4Pin