Wanhua ruler was popular around the end of the last century80-90In the era, the common mother ruler was an inner ring gear, and the sub ruler was an outer ring gear with porous teeth. With this multifunctional Wanhua ruler, we can draw many incredible and beautiful patterns, and everyone who has played Wanhua ruler will be amazed by the wonders inside. The patterns produced by the versatile ruler are unique and wonderful, and each style can stand alone. The complex and exquisite patterns originate from a simple tool. Today, let's start making a magical kaleidoscope with ease and relive the beautiful times of childhood.