SIT = Somewhere In Time
SS = Seventh Son
Gallien Krueger guitar amps were all over the future 80's tones.
Iron Maiden, Rush, Queensryche, Judas Priest, Bon Jovi, Motly Crue, Extreme, ZZ Top, all used them for an iconic album or two.
https://www.youtube.com/watch?v=UJsl-bB7lmk