This is the style bridge used on many "hippie sandwich" Guitars in the 70's-80's including Jerry Garcia's Alligator Stratocastor. Bridge saddles are unslotted. 3/4" square brass sustain block and adjustable posts through the top with a 1/8" allen hex wrench and locked in place with a top 10-32 round head brass screw. Saddle adjusting screws are washered with brass and nylon on both sides for smooth operation. Post spacing is 2.912" (74mm) Thanks! Will S.