Metal underwires add structure and lift to larger cup or band combinations. This pair is sized for selected 40B, 38C and 36D combinations; verify against fit charts and your pattern’s wire line. Insert with the blunt tip toward the center front and the rounded tip toward the underarm, then bar‑tack ends securely to keep wires in place. Choose size/type to match fabric and project needs. Test on a scrap and follow package directions for best results.