Chalk from around the 1970s. This chalk was used for drawing on blackboards, and this set includes 6 yellow pieces! The manufacturer is Nippon Hakuboku Kogyo Co., Ltd., and the product name is Tenjin Shikihakuboku. The condition is unused, so it's old, but it can be used normally. It has been carefully stored in a warehouse since around the 1970s. I have other colors for sale as well, so how about taking a look? Due to the increase in shipping costs, I will slightly increase the price. Instant purchase is OK.