The Sheldon clamp is a tool used for male circumcision.

The clamp has two sets of jaws. The first set grasps the acroposthion (tip of the foreskin), and the second set grips the tube just in front of the glans.  The cut is made between the two jaws.  Care must be taken by the operator to ensure that the glans does not become trapped in the clamp, prior to excision of the foreskin.

Image Source: www.circlist.com/instrstechs/sheldon.html