Paper Type: Premium Heavy Thermal Paper (78gsm - 80 gsm) designed specifically for the Zebra ZQ520. Paper will also work in any machine that accepts 4 inch width and 2 1/4 inch roll diameter. This includes: Zebra P4T, Zebra QL 420, Zebra QL 420 Plus, Zebra RW 420, Zebra ZQ520, Zebra ZQ500 series Great for mobile printing applications such as police tickets, delivery, warehousing, receipts and more.