EFT16 Flat Top strings combine D'Addario's popular medium gauging with an exclusive precision polishing process for a smoother, quieter playing surface. Great for recording or slide playing. Environmentally friendly, corrosion resistant packaging for strings that are always fresh. Made in the U.S.A. for the highest quality and performance. String Gauges: Plain Steel 0.013, 0.017, Phosphor Bronze Wound 0.026, 0.035, 0.045, 0.056.