Use Your Head. The SureFire 2211 Headstrap adds to the versatility of any 2211® WristLight by allowing you to quickly convert the WristLight into a headlamp. Simply buckle the 2211 WristLight into the headstrap and then adjust the strap to comfortably and snugly fit your head (one size fits all) for instant hands-free illumination. It’s perfect for tasks where you need both hands and need the light source to be relatively stationary and farther back than your wrist, such as when changing a tire at night, working on an engine, loading gear or navigating a dark pathway in the great outdoors.