Tung-Sol Tube Upgrade Kit For Fender Custom Vibrolux Reverb Amps 6L6GCSTR 12AX7 12AT7W (No Rectifier) This set includes (2) Matched Tung-Sol 6L6GCSTR power tubes (4) Tung-Sol 12AX7 preamp tubes (1) "Gain Balanced" Tung-Sol 12AX7 preamp tube (phase inverter) marked with yellow "Balanced Triodes" Sticker (1) Tung-Sol 12AT7W preamp tube