Using Silk's special winding topology for extended bandwidth and detail retrieval
Primary Impedance: 3K
Secondary: 4/8/16
frequency Response: 20-45,000Hz
Power Rating: 12W
Max current: 100mA
Inductance: 10h
Size: 6 x 7 x 9.5cm
Shipping Weight: 1.5kg

Suitable for: 2A3, 6B4G, PX25A, 6F6,6V6

These are much too good for the money