ThermaLock 4100D from Zebra is the direct thermal label you need if you need it to withstand the harshest environments. All weather conditions, including extreme heat and cold, direct sunlight, rain, snow, and chemical exposure are no match for this direct thermal label. For up to a year outside, and even longer indoors and in shaded areas, the label is clear and highly legible with simple-to-scan barcodes. Use it in indoor and outdoor facilities as well as out in the field thanks to compatibility with Zebra's direct thermal mobile, desktop, and industrial printers. ThermaLock 4100D is Zebra's most durable direct thermal label to date thanks to new technology, which also increases chemical and moisture resistance in this iteration of the dependable and well-liked ThermaLock 4000D.