6X4 (EZ90) TUNG-SOL Black Plates Square Getter Vacuum Tube Rectifier M – Vacuum Tubes Treasures
6X4 Tube Full Wave High Vacuum Rectifier, Various US Brands. Miniature heater-cathode type twin diode designed for full-wave rectifier operation in compact power supplies. MFR: RCA. SKU: 6X4. New old stock. No
Tubes-Store.com → Rectifier tubes → 6Z31 TESLA rectifier tube. Equivalent to the 6X4 / EZ90.