Harp Tuning Pins, Brass, 3 1/8", 6-Pack (Item Code: HTNPBL) They are approximately 3 1/8 inches long (79mm). The peg is tapered over its length; the narrow end has a hole to accommodate the string and is 0.23 inches in diameter, the wider tuning end is 0.25 inches in diameter (5.8 to 6.4mm). These pins are solid brass and handmade so expect some variation in size. To change your tuning pin, remove the string and place your tuning wrench over the string end of the pin. Then tap on the wrench to tap the pin out through the harp arm. Replace the pin by inserting from the tuning side. Place the tuning wrench on the tuning end of the pin and tap it into place. The tuning ends of the pins should all be aligned. If necessary, wooden toothpicks make great shims. These tuning pins are meant to fit the following Roosebeck(TM) harps: HMGA: Meghan Harp(TM) and HRB38: Christal Harp(TM).