1975 Fender Twin Reverb Silverface master volume with amp cover and reverb/vibrato footswitch.  This is a super clean, beautiful vintage amp with a killer tone.  It has been regularly maintained to spec, original parts with exception to the replacement speaker and footswitch as pictured.  Both Normal and Vibrato channels have the classic rich Fender Twin tone.  The tremolo and reverb on Vibrato channel are quintessential Fender and sound amazing.  I will mention that when pushed past ~8, the reverb begins to decay and will typically produce a feedback, but is otherwise very dynamic and can add great subtle atmosphere to shimmering surf-rock tones.  The tremolo is knockout.  The Bright switches on both channels do their thing. 

The Twin Reverbs of 1975 are 85W all tube, 2x12 speakers and are renowned for having big headroom.  The master volume is a great feature on this amp that was introduced to the Twin in the 70s and allows you to dial-in each channel's volume for earlier gain onset.  I typically turn channel volume ~5 or 6 and adjust Master depending on venue and how loud everyone else is.  Also, little known feature is the push-pull boost on the master volume knob which adds a different tone quality (very slight overdrive-with-compression to my ears).  

Cosmetically, this amp has the distinguished antique look you would expect from a 40+ year old.  The cabinet, tolex, grill cloth, and baffles are in fantastic shape.  The metal and aluminum has a nice vintage patina.  I've included a picture of the only (barely) visible imperfection--a minor repair in the tolex on the bottom edge.