 Transgender men and people with other gender identities (typically male presenting) may bind their breasts as an alternative to or while waiting for a "top surgery" (mastectomy) in order to be recognized as masculine presenting.Men may also find cause to bind if afflicted with gynecomastia as a means to control appearance in place of surgery or during the wait before surgery.Purpose-built undergarments known as binders or binding bras exist (often using spandex or other synthetic fibre), and are commonly used for breast binding.