Sizes include 

90mm + 140mm + 200mm

A Balfour retractor is a surgical instrument which is used by a surgeon to hold open abdominal incisions during a laparotomy. Retractors of all shapes and sizes are used to clearly expose the surgical site during surgeries so the surgeon can see what he or she is doing, and they work in a variety of ways. In the case of a Balfour retractor, the device holds itself in place, leaving the hands of the surgeon and assistants free to focus on surgical tasks.