Kerly bass guitar strings are seasoned between -320F and +350F for 24 hours to reduce the microcracks that cause tonal loss and premature breakage. Thanks to the repetitive HOT/COLD tempering process, the microcracks close up, preventing the buildup of dirt and corrosion. Strength, sound, and string life are enhanced. Made from the finest metals, they are crisp, full-sounding, tough, and long lasting. Thermal Cycling increases tone and keeps your strings sounding new for a longer period of time. No more boiling or using peroxide. Set of 5 medium gauge strings.