Specam Piano Tuning Hammer Lever Wrench L-shape Piano Tuner Spanner L-shape design, easy to use it. Small and exquisite, convenient to carry it. Specially designed for tuning guzheng and most machine devices that have quadrilateral openings. The metal shaft is made of hard steel, abrasion resistance. Note: Please measure the tip size of your device before purchasing, make sure the size of your devices match with the wrench quadrilateral.