A 400um nylon mesh filter bag, with zip (300mm long x 300mm layflat) flat bottom. The "um" denotes micrometer (or microns).
A compost extractor bag ("brew bag") is a specialized mesh container used to submerge high-quality compost or worm castings in water to create a liquid biological inoculant.
The goal is to "wash" or extract beneficial microorganisms—such as bacteria, fungi, protozoa, and nematodes—off the solid compost and into the water so they can be easily applied to gardens or crops (foliar sprays or soil drenches).
