The ESAB EPR-X1 pre filter for ESAB EPR-X1 PAPR units.
ESAB’s fresh air fans are supplied with a main filter of the P3 type which gives the highest HEPA filtration efficiency – 99.8% according to ESAB. The pre and main filters, filter out both both solids and vapour bornedamaging particles in the smoke. This means that particles containing aluminium, barium, cobalt, chrome, copper, manganese and nickel are caught by the main filter. 
Supplied as a pack of 5