Made from natural pH-neutral, industrial hemp fibers. Cleaner to use than soil mix and 100% biodegradable and compostable. Hemp has a high water-holding capacity, keeping seeds moist through germination. Made with biodegradable backing for added strength. Compatible with all 1020 bottom trays and Microgreens Growing Trays (#6796). Made in Canada. Dimensions: 10″ x 20″. Quantity: 140 mats.