"Needed some dust and formaldehyde protection as I was starting work making MDF plaques for a craft club. After the usual search for what worked best, ordered these from Screwfix via Click & Collect so I could get started. Good firm fit to the JSP 1/2 mask and have been very satisfied with the way they work. Scroll sawing and sanding MDF produces a lot of fine dust so these are an essential work aid. Also saves me from having to think about actual hours worn rather than checking their continued effectiveness."