The Pica Big Dry Refill Set Special Assorted Colors Permanent (SB) includes a variety of high-quality refills designed for Pica Big Dry mechanical pencils. These refills come in multiple vibrant, permanent colors, making them ideal for tasks that require long-lasting, visible marks, such as drawing, marking, or labeling. The "SB" designation suggests that these refills are especially suited for permanent applications, providing clear, durable lines that won't fade easily. This set is perfect for professionals or creatives who need a range of colors for precise and permanent markings in various environments.