Stanley FatMax XL Square Bottle Chalk Refills - Stanley 9-47-821, Powder specially formulated for good adhesion and high visibility. Waterproof non-clumping so can still be used if soaked with water. Suitable for for interior and exterior use.Red is suitable for external masonry work. Indelible.Size 225g. Stanley 9-47-821 FatMax XL Square Bottle Chalk Refill 225g Red Stanley STA947821 FATMAX Chalk Refill Red 225g Stanley FATMAX Chalk Powder is specially formulated for good adhesion and high visibility. Its weather resistant formula will not fade or bleed in a wet environment. It also prevents chalk from clumping inside the chalk reel meaning it can still be used if soaked with water. Suitable for both interior and exterior use. It is specifically packaged in a square bottle which is designed to not roll off work surfaces. 1 x Stanley FATMAX Chalk Refill Red 225g Red is suitable for external masonry work. Indelible.