The AES Weld Cube Filter Pack is a set of replacement filters to suit your Weld Cube unit. This HEPA Filter Pack contains: 1 x Metal Mesh pre filter which acts as a spark arrestor to stop any sparks to reach the second and final filters. 1 x Synthetic Filter to arrest any oils or wet parts caused by the welding 1 x Pocket Filter (HEPA 13) - filters the finer dust and fume particles The filter pack for the AES Weld Cube contains a replacement filter for each of the three filtration stages within the unit. The first filter is constructed from metal mesh and is ideal for the initial pre separation of hot particles and sparks so that they do not reach the remaining filters. The synthetic filter in the second stage is positioned to separate any residual materials from the weld such as oil and paint that may be on the workpiece. The final filter is a HEPA H13 grade pocket filter constructed from antistatic polyester Teflon membrane to reduce exposure from the finer dust and particles from the welding fume.