D baroque violin silver open wound type "FD" (length: 55 cm.) Light (108 equiv gut) - 4FD Medium (112 equiv gut) - 5FD Heavy (116 equiv gut) - 6FD Aquila Product Information As far as we know, our “FD” type strings (demi fileé in pure silver) are based on the constructive proportions and the typical materials used between the 18th and 19th centuries for wound strings. Note: Due to the spacing between the coils of the metal wire, this type of string is extremely delicate. During the first tuning phase it is therefore advisable to lift the string a few millimetres above the groove of the nut and the bridge, and let it go only when the required pitch is close. As a matter of fact, the spacing of the winding, due to its nature, does not allow the string to slide in the grooves. In this way the risk of damaging the wire is eliminated.