The Pica Big Dry Refill Aniline All Weather Leads are specially designed refills for Pica Big Dry mechanical pencils. These leads are made with aniline, a dye-based material that allows for highly visible markings. The "all weather" feature makes them suitable for use in various conditions, such as on wet, oily, or dusty surfaces, providing reliable marks even in challenging environments. These refills are ideal for professionals and DIYers who need durable, clear markings for construction, woodworking, or other outdoor tasks where standard pencils may fail.