To provide a sign capable of easily changing between three different displays by one sign, which conventional double-sided sign has to be changed backside front from "IN PREPARATION" to "OPEN" before opening a shop, and to "IN PREPARATION" when closing the shop; or to "CLOSED" on a regular holiday using or overlapping with another sign.

A triangular prism which having three display faces is horizontally disposed between two support posts. Each of the three display faces has one different message thereon. When the triangular prism is rotated, three different messages can be displayed easily by one single sign.