[Used] Mesa Boogie Genuine Vacuum Tube 6L6 GC STR440 I had it changed to EL34 during amplifier maintenance at a famous shop. I like the current sound, so I'm going to sell this vacuum tube. It produced sound without any problems when installed, but its current condition is unknown. No original box. It will be placed in another vacuum tube box, wrapped in bubble wrap, and shipped via Yamato Transport's Compact service. Please refrain from purchasing if you are concerned or if you are not comfortable with used items.