Trade quality builders / carpenters chalk with good adhesion Brightly coloured blue builders chalk powder refill 8oz (236 grams) of quality blue chalk powder per bottle This listing is for 2 x bottles of blue chalk so 16oz (472 grams) Suitable for use with chalk line reels Handy nozzle cap squeezy bottle with easy pouring spout Suitable for both internal and external use Chalk is perfect for drywall, wood, concrete, stone and more Twist cap lid for safe easy storage Weather resistant chalk and non clumping so can be used if it comes into contact with water