<unk><unk> 's self-retaining bivalved<unk>  is a surgical instrument used for vaginal and cervical examination. It has a jaw that opens up like a duck bill. The instrument was named after French surgeon Édouard-Gabriel<unk>  (1819–1894). It comes in three models: side screw, centre screw, and special narrow virgin size.<unk>  is usually long and broad. However, smaller and larger sizes are available.<unk>  is used for introducing an intrauterine contraceptive device, taking a Pap smear, cauterization of vaginal erosion, and colposcopic examination. It is preferred in cryosurgery because it protects the anterior and posterior vaginal wall. The advantage of<unk>  is that it is self-retaining. Therefore, an assistant's help is not needed to keep the<unk>  in place. It also acts as the vaginal wall retractor. However, it reduces the space in the vaginal cavity and therefore is not a preferred instrument for vaginal surgery. Because it covers most of the vaginal wall, small lesions on the vaginal wall may be masked by the blades of the device.
Cusco's speculum
Tycoon's cap
Krukenberg's spindle
Curschmann's spirals
Sebaceous filament
Mees' lines
Floor plate
Hematoxylin body