La Bella Jazz Tapes® are the secret behind the sound of the best professional jazz players in the world. These strings are handcrafted with a proprietary black nylon tape, wound on a hexagonal core. The result is a flat and extremely smooth string, producing a warm, jazzy sound with zero finger noise. These professional Jazz Guitar Strings are made to fit archtops and hollow-body guitars, therefore are not suitable for standard guitars with 25.5” or 24.75” scales.-Black Nylon Tape for warm, jazzy tone-Tension: Regular-String Gauges: Plain Steel .010, .013, .017, Black Nylon Tape .026W, .036, .046-Made in the USA with American Wire-Packaged using MAP Technology (Modified Atmosphere Packaging) to prevent tarnishing and ensure freshness