Floyd Rose Tremolo unit with locking string mechanism therefore he is slightly readjusting the tune of a string with a small knurled knob at the back of the bridge.

He loves to flick between his pickups with great effect (not just visual as you an hear a difference - might be a multi switch not just a 3 way) and the 2 knobs on the body would seem to be a master volume & master tone.

South American 'amplificador wenstone guitarra' as found at this link http://articulo.mercadolibre.com.ar/...ltiuso-65w-_JM