This product is designed for positioning on a piano code or to check the string pillow position of an existing piano code. It can adjust string lengths up to 27 inches and features positioning nails for optimal chord length compensation. Constructed from aluminum alloy with special screws, it ensures durability and accuracy for piano tuning and maintenance. Product features: Quickly and accurately find the correct position of the piano code slot, locate the slotted position of the string pillow on the piano code, and check the accuracy of the existing lower string pillow position. When removing the current piano code, record the original position of the pillow, which can be checked without removing the strings. Color: Silver Material: Metal Package Contents: 1*Rangefinder(Knob colors are random) 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.