On 6 colors DCC-72-6C 72 units in Japan physics and chemistry da stress choke (japan import)Dustless Chalk 72pcs, 6 colors The most popular chalk in Japan since 1937 Writes well and clear on the blackboard, feels soft and smooth Eco-friedly product, made from calcium carbonate and scallop shells Lasts twice as long as gypsum chalk thanks to lower wear factor. Coated body keeps your hand clean. Made in Japan