It is said that the performance and durability of open-gear machine heads is inferior to sealed-gear (Rotomatic) types. Because the bushing is physically separate from the machine head body it is difficult to accurately position the string post through it when mounting onto the guitar. To solve these problems the SXB510 series includes a centering guide at the base of the body to ensure a flush fit combined with Rock Solid string posts. Also, the SXN510 series employs a nut mount system and can be installed as a direct replacement into the same holes drilled for Rotomatic style tuners. The improved performance and durability which the SX510 series provides, thanks to GOTOH’s unique design and manufacturing, gives you the chance to experience a sound you’ve never heard before.