Russian guitar usually differs from the wood in the rest of the neck. The neck joint or heel is the point at which the neck is attached to the body of the guitar. The fingerboard is made of hardwood (ebony or rosewood are common), fitted with metal frets of brass or steel. Fret spacing almost always follows the western twelve tone equal temperament (12-tet) system. The surface of the fingerboard may be flat or curved slightly ("radiused"), although the curve on the Russian guitar is usually somewhat less than that of an equivalent western 6-string guitar. Inlayed position markers are common, and
Scale length (string instruments) construction using the Novax Fanned-Fret system that "fan outward" for the ability to play in tune with the unequal scale lengths of each string that is used to find the optimal equal tonal response and equal string tension from string-to-string for easier playing is represented by Dingwall Basses, who uses a 37" to 34" span on their Prima, Z1, Z2, and Afterburner original designs and a shorter 34.25" to 32" span for their "Super J" Jazz Bass design. Helios R-Evolution 7 strings bass Heliosguitars Helios ANTARES 6 strings bass Heliosguitars The scale length of a piano is the length of