Fits onto the brim of hard hat or bump cap. Worn in conjunction with existing safety eyewear. Integral spring clip holds them securely without the use of screws fasteners or tools. Quickly flip down to enhance vision then flip up when not needed. Available in half or full lenses in green welding shades 4 5 6 8; and cobalt blue shades 4 6 and 8; and didymium full 48mm lift front filters.