My Favorite Chalk Sidewalk and Blackboard Chalk Bucket. With this fun set of sidewalk chalks you can make the nicest and most beautiful sidewalk drawings. This sidewalk chalk is also suitable for use on a blackboard and is completely harmless and therefore very suitable for children. Specifications: Supplied in a resealable storage bucket. Easy to clean. Material: Chalk Length per chalk: 9 cm Diameter per chalk: 2 cm Number of chalks: 20 Chalk colors: White / Yellow / Orange / Red / Blue / Green / Brown Contents: 20 Sidewalk chalks in different colors. Storage bucket.