The 820 Flamenco sets contain red nylon trebles and silver-plated wound basses. Especially designed for the flamenco player, this set produces extremely brilliant tones with only the slightest left hand finger pressure.- Bright Tone- Tension: Medium- String Gauges: Red Nylon: .028, .032, .040, Silver-Plated Wound: .028, .033, .041- Made in the USA with American Wire- Packaged using MAP Technology (Modified Atmosphere Packaging) to prevent tarnishing and ensure freshness