Mask fastening strap length adjuster

摘要

An adjuster for the length of fastening straps on a face mask (2), e.g. used for protecting the nose and mouth from dust penetration, consists of a thin strip of an elastic material, e.g., polypropylene, with a slot or holes (5) with slits (6) in one end to receive one of the mask straps (3), and a series of hook-shaped elements (4) along its length to engage with the other strap (3'). The hook-shaped elements (4) project from both upper and lower edges of the strip and are inclined towards the rear of the strip. When used the strip is fastened to one of the straps and taken round the back of the head to engage with the other one.