A watch strap, watch band, watch bracelet or watch belt is a bracelet that straps a wrist watch onto the wrist. Watch straps may be made of leather, plastic, rubber, cloth, or metal, sometimes in combination. It can be regarded as a fashion item, serving both a utilitarian and decorative function.
Most smartwatches use either a 22mm or 20mm strap. There are also those that use 18mm straps. In some cases, it is the size of the dial you have to note. For example, if it is an Apple Watch, it can be 38mm, 40mm, 42mm, or 44mm.