Wilson's latest addition to the NXT family of strings comes in the form of NXT OS. With its unique multifilament construction, NXT OS offers a gut like feel with superior tension maintenance compared to other multifilament synthetic gut strings. Note: At 45 feet, NXT OS is suitable for Super Oversize applications. Gauge: 16 / 1.28 mm. Construction: Solid center core with bundles of multifilament fibers in a rope like wrap, PU outer coating. Length: 45 feet / 13.7 m. Color: Natural.