IRWIN Tools STRAIT-LINE Permanent Staining Marking Chalk, Indigo Blue, 4pound (4935524) Great for extreme outdoor conditions because it can withstand harsh weather conditions and months of jobsite wear. Flip-cap keeps the chalk in the bottle where you want it and stops it from spilling out in areas that you don't. Flip-top cap also seals the chalk in an airtight chamber, keeping out moisture and reducing the risk of clumping. IRWIN Tools STRAIT-LINE Permanent Staining Marking Chalk, Indigo Blue, 4pound (4935524) Features Great for extreme outdoor conditions because it can withstand harsh weather conditions and months of jobsite wear. Flip-cap keeps the chalk in the bottle where you want it and stops it from spilling out in areas that you don't. Flip-top cap also seals the chalk in an airtight chamber, keeping out moisture and reducing the risk of clumping. USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.