Developed by La Bella's president Richard Mari Cocco, Jr. with Ned Steinberger, these strings have been manufactured to exact specifications for Steinberger's revolutionary headless instruments. Calibrated for the correct length and tension needed for “Trans-Trem” non-transposing Steinberger instruments Not suitable for any instruments made by Gibson Corp. , including Spirit Instruments Stainless Steel Round Wound Tension: Extra Light String Gauges: . 009, . 011, . 016, . 024W, . 032, . 042 Made in the USA with American Wire Packaged using MAP Technology (Modified Atmosphere Packaging) to prevent tarnishing and ensure freshness