The screen is made of high quality, 304 grade, certified wire mesh for perfect screening. The side rim is made of brass which is known to resist the water. The mesh is machine inserted into the rim and the sides are plastered with the plastic gum for closing the contact point to reject the possibility of hiding immatures larvae.
The 4 and 2mm screens are used to clear the large debries from larval samples. 250µm tiny enough to screen insects upto 2nd instar larvae