The Two Rock Sterling Signature head is the SSS amplifier built in the early years of the company's trail blazing run. Limited to only 10 amplifiers this is Serial Number 6. I sold this amplifier new to one of Two Rock's best client's and it's remained in his collection till now. This is a rare chance to acquire this amplifier as we're only putting this up for a limited time before it goes into the Watchtower amplifier collection. The amp is mint and if you have any questions please let us know. I'll also be listing several rare limited Two Rock's from this collection including a Sterling Signature, Kimock Signature, and the very first Overdrive Signature that was built by Bill Krinard himself. To the buyer who hits the buy it now price on this Mayer amplifier I have a rare and special treat - a limited matching carbon fiber Sinewave 2x12 cabinet loaded with Two Rock speakers that was commissioned for this build. There's not another Mayer with that cabinet. Please let us know if you have any questions.