The mask strap is the piece of elastic silicone which wraps around the head and holds the mask securely in place when being worn. The position of the mask strap is important in determining how it fits and how well it stays in place. The mask strap should be worm snugly but not too tight, around the head and rest directly on the crown of the head. Wearing the strap too far above or below where the mask rests can cause discomfort or mask leakage. Here is a helpful tip. Strap wrappers are an additional accessory to the mask strap which many people find useful. It is a small band of neoprene which is put around the mask strap to help the mask strap slide on and off easier as well as stop the silicone from snagging long hair. Mask straps wrappers are usually very inexpensive and are available in a wide variety of fun colors and designs.