This mesh is made of Nickel metal and is ~90% transparent to electrons. The mesh is sitting on a 3 cm x 3 cm square of aluminum metal. The mesh-screen is sitting < 1 mm above the surface of the sample. The mesh is held down using aluminum tape. The holes can be used to trap the mesh-screen with screws. The mesh screen needs to be connected to ground. If you use a magnetic lens, then you should use a non-magnetic metal, not Nickel. (Nickel works, but it moves up and down.) If your X-ray beam is small, then the mesh needs to be closer to the sample, maybe ~0.5 mm. If the mesh touches the sample, you will see the Nickel signal in your survey spectrum, but not your chemical state spectra.