Used to secure the cuffs of dress shirts, cufflinks are an elegant alternative to buttons, which are usually sewn onto shirt cuffs as a way for fastening them closed. Worn in pairs, they are most often used for semi-formal or formal events. Cufflinks can come in a variety of materials as well as finishes, shapes, sizes and styles. Some also include gemstones. Different types of cufflinks include knot, ball return, chain link, bullet back, whale back and more.