Pica Visor Blue Refills, 4PK come in a convenient carrying case designed to keep your refills organized and ready for use. These refills are made for the Pica Visor marker and are suitable for marking on all material surfaces, ranging from glossy to very rough textures. They extremely water-resistant marking that is both versatile and reliable. The lead dries out, ensuring full performance from the very first line to the last. For optimal use, avoid applying on surfaces with temperatures above 104°F (40°C). Each refill has a lead diameter of 10 mm and a length of 85 mm. Model Number: 991/41