Irwin Strait Line 4 oz. Red Powder Chalk is a high-quality chalk that is perfect for marking lines on a variety of surfaces. It is made from calcium carbonate and red iron oxide, and has a specific gravity of 3.3 to 3.35, a relative density of 3.4 to 3.45, and a pH range of 8.5 to 9.5. It is odorless and comes in a plastic bottle. IRWIN STRAIT-LINE Marking chalks have a newly engineered flip-top cap that keeps the chalk in the bottle where you want it and stops it from spilling out in areas that you don't. The flip-top cap, available on all IRWIN STRAIT-LINE chalk bottles, seals the chalk in an air-tight chamber, keeping out moisture and reducing the risk of clumping.
- 4 oz. bottle
- Red powder chalk
- Made from calcium carbonate and red iron oxide
- Specific gravity of 3.3 to 3.35
- Relative density of 3.4 to 3.45
- pH range of 8.5 to 9.5
- Odorless
- Comes in a plastic bottle
