Rion Co., Ltd. engages in the manufacture, sale maintenance services of hearing instruments, medical equipment, sound and vibration measuring instruments, and particle counters. It operates through the following segments: Medical Equipment and Environmental Equipment. The Medical Equipment segment manufactures and sells hearing aids and medical testing equipment. The Environmental Equipment segment produces fine instruments as well as acoustic and vibration measuring equipment. The company was founded on June 21, 1944 and is headquartered in Tokyo, Japan.