This is a porous filter foam with a uniform cell structure.
The foam is used where porosity, a high surface area, or a low density is important. Applications include air filters in air conditioners and vacuum cleaners. It is also used for water filters in aquariums, loudspeaker covers, and fuel tank inserts. A mesh similar to the sample with the large holes is used in an investment casting process to create open-cell aluminium foam.
You get two sheets with different porosities measuring 20 cm x 14 cm with a thickness of 8-9 mm. The high porosity sample has 10 PPI (pores per inch) which equals cell sizes of ~5 mm. The low porosity sample has 75 PPI which equals a cell size of ~0.5 mm.
All samples come with a laminated information card.