KR Audio PX25 - Low Frequency, high power triode. 5-10 Watts of pure class-A power. Maximum Plate Voltage 500 V Maximum Plate Current 90 mA Plate Dissipation 30 Watts Va 400 V Ia 63 mA Vg -31 V Transconductance 7.4 mA/V Amplification Factor 9.5 Filament Voltage 4 V (DC/AC) Filament Current 1.8 A SPECIAL ORDERED ITEM.THIS ITEM IS MADE TO ORDER.ALLOW 4 TO 6 WEEKS DELIVERY AFTER INITIAL ORDER.