CleanSpace Filter Adaptor must be in placed when using the CleanSpace large case filters: PAF-0037, PAF-0091, PAF-0050 and PAF-0051. The Power Unit cover is removed and replaced with the Filter Adaptor, which the large filters are then clipped in place.IMPORTANT: When selecting a CleanSpace Filter please consult a Health and Safety specialist for advice on the appropriate respiratory equipment and filter use. Used with the revolutionary CleanSpace PAPR: light weight, no hoses or belts Suitable for use with all CleanSpace large filters: PAF-0037, PAF-0091, PAF-0050, and PAF-0051 Materials: Plastic casing, silicone seal and steel fasteners and stainless steel springs Easy and quickly fitted and removed from the power unit Specifications: Weight: average 113g Dimensions: 180mm x 100mm x 80mm Storage and Use: –10°C to +55°C (–4°F to +131°F) at