Irwin Strait-Line Permanent Chalk Line Chalk, 8 oz. is designed for use with reel type chalkline boxes and comes packaged in a convenient plastic squeeze bottle with a fast fill spout. This chalk is i for exterior applications on a variety of surfaces including wood, drywall, concrete, stone, and metal. Its permanent colors create long-lasting lines that resist fading, remaining visible even after weeks of exposure to weather and jobsite wear. The red color is vibrant and reliable, making it a dependable choice for marking and layout tasks. Model Number: 64902