Rion Co., Ltd. engages in the manufacture, sale maintenance services of hearing instruments, medical equipment, sound and vibration measuring instruments, and particle counters. The company is headquartered in Kokubunji-Shi, Tokyo-To and currently employs 1,009 full-time employees. The company went IPO on 2000-05-15. The company operates through three segments. The Particle Counter segment manufactures and sells particle counters such as liquid particle counters and airborne particle counters. The Medical Equipment segment manufactures and sells hearing aids and medical testing equipment. The Environmental Equipment segment manufactures and sells sound and vibration measuring instruments such as sound level meters, vibration meters, seismometers and frequency analyzers.