Is there a medical device called a duckbill? What is its function?

The dilator, also known as the duckbill, is a tool commonly used in vaginal examinations, the dilator is sterilized by autoclave, sterile, dilation, the doctor will put on disposable gloves, and then the closed dilator slowly and gently into the vagina, and then slowly expand, fix the size of the opening in order to facilitate the examination of the vagina.