This is the screw that locks the saddle in place after intonation of the "Traditional" fulcrum tremolo. 

Length: 0.0000 in
Width: 0.0000 in
Height: 0.0000 in
Weight: 0.100 oz
Packaging: 0.0000 kg
Units in box: 1
Parts by Make/Model > Kahler Parts > 25xx Traditional - Fulcrum
Parts by Type > Saddles > Saddle Hardware