This is electric guitar-style hard-tail bridge, but made for 3-string guitars! It took us a long time to find a source for these, but now we got 'em! These bridges are "top-loading" style, which means that the strings are fed through the back plate of , then up and over the saddles. No drilling through the instrument/box is required! Each one is mounted securely by four screws, and a small Hex Wrench is also included for adjusting the small set screws that control string action height. See the listing photo with measurements (in millimeters) for more size specs. Color: Black Material: zinc alloy Size: 50 x 40 x 13mm Chord spacing: 12mm Package Contents: 4 x Guitar Bridge 4 x wrench 16 x screw Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.