Killermaru wrenches are by far the most exotic tension wrenches available. Designed to maximize the tension and feedback created from a mix of springs and levers these tension wrenches allow for a greater feel and a true indication as to how much tension you are applying.
When setting pins the click can resonates though the wrench in a way that you do not feel from a single bent wrench. These wrenches are truly different.
This is for a two wrenches each unique in design.