VIVOSUN 1-Gallon 4-Bag Herbal Ice Bubble Hash Bag Essense Extractor Kit Filtration Bags/Set (1)Purple=25Micron(2)Yellow=73Micron(3)Red=160Micron(4)Blue=220Micron Bubble extraction bag is made of long lasting nylon material, prevents from flaking and chipping after several uses. Package comes with free 25 micron pressing mesh screen and storage bag. Corresponding color micron bags are labeled for proper order. The smaller micron screen is, the less crystals escape, the better filter performance you will get. Varied microns of bags allow filtering herbal resins into different grades to meet your need.