Immuson Labels- 4"x6"(101mm x 152mm), 250 labels per roll, total 20 rolls = 5000 labels. 1" core, It is only suitable for thermal printers, DO NOT for Dymo printer and laser inkjet printers. High Quality Labels- waterproof, oil-proof, resists scratches / dirt / dust / grease. Great for your warehouse and packages. Commercial Grade Labels- Peel & stick extra-large labels with strong self-adhesive backing. We use premium-grade and powerful adhesive enabling each label to long-time stick to any packaging surface tightly. Strong Compatibility Labels- Compatible with MUNBYN, MFLABEL, Zebra, Rollo, Arkscan, BESTEASY, iDPRT, JADENS, Phomemo, Polono, Jiose, K Comer, LabelRange, OFFNOVA, HPRT, NefLaca and other direct thermal printers. (NOT Compatible With DYMO and Brother). Fade Resistant and Reliabel Labels- Labels are made of upgrade material that you can print crystal clear images and easy to scan and easily to peel off due to perforated line.