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Tuning wrench sockets may be triangular-shaped or eight-pointed star-shaped, and are found in two basic sizes: a large size for pianos, and a smaller size for most other instruments. For pianos, pins are typically square with a slight taper. There are three standard sizes known as No. 1, No. 2 and No. 3, for pins up to 6.5mm, for pins 6.5mm to 7.25mm, and for pins larger than 7.25mm. No. 2 is the most common. Wrenches are supplied with an eight-point star.[1] Some early keyboard instruments have oblong-shaped tuning pins.