we are reliable manufacturer for steel filter mesh which are used in the Smoke detectors filter mesh for Smoke detectors All the micro filter meshes are chemical etched, Smallest hole diameter can be 0.1 mm when the material thickness is below 0.05 mm, filter hole open area more than 75%, hole shapes can be round, square, Hexagon or customized.Generally, the thickness of mesh is 0.1 mm, 0.15 mm, ...