OldPAPA rosin filter bags are designed for rosin press.It’s a good rosin extraction tool.Durable, Washable and Reusable Rosin filter bags.Each bag can hold about 10-12g of given material.Come already inside out stitching and with mech opening.Our 2×4 inch design fits most heat plates for your rosin tech.Our Rosin bags are available in 25 Micron,37 Micron,90 Micron,120 Micron,160 Micron.Ask us about custom size,if you need.Micron is the size of the hole in the mesh per inch.The higher of the micron number, the cloth hole will be larger.Choose your micron size to determine how to refine your final product.Package Included: 50 Pcs of Rosin Press Filter Bag.