barton watch bands bars21 stainless steel watch pins, 21mm, pack of 4 barton watch bands each package contains four stainless steel spring bars. all widths (18, 19, 20, 21, 22, 23 or 24mm) are 1.8mm in diameter and have double shoulders on each end to ease the installation process.</br></br> designed to fit watches with lug widths of 18mm, 19mm 20mm, 21mm, 22mm, 23mm or 24mm. to determine proper width, measure the width between watch lugs at the point where the band attaches or consult manufacturers specifications (typically available online). after determining width, click your heels three times and select the width from above that corresponds to measurement.