The ability to withstand the stress of twisting and bending, flex strength is important in wire and cable applications that involve frequent bending and twisting. Illustrative applications include elevator telephone cables, telephone handset and headset cords, and microphone cords. Wires and cables designed for high flex strength commonly involve small diameter conductors and cables, stranded rather than solid core conductors, stranded or braided rather than solid metal shields, conductors and shields made of metal alloys that are flexible, and insulation made of materials that are not only flexible, but also abrasion resistant. See also break strength and tensile strength.