Made of Stainless Steel, does not readily corrode, rust, or tarnish with water, which is strong and durable, and keeps your watch safe. The pin works by having an inside spring that pushes out the ends to make the pin hold onto the watch very well.The ends of the pins are double flanged and have a spring at the end of the bar that allows for easy removal and installation. Great for watch band replacement, and watch repair. Suitable for traditional watches and smart watches which lug width is standard 14mm Notice: Measure the width between the watch lugs at the point where the watch band attaches. This would also be your watch band's attachment width. 1.5mm diameter pins fit all leather watch straps and fine mesh steel straps; 1.8mm diameter pins fit coarse mesh steel straps.