Tohtsu Co., Ltd. is a Japanese manufacturer specializing in high-frequency electromechanical components, founded in 1954 and headquartered in Yokohama, Kanagawa, Japan. The company's core business revolves around the design, development, and production of RF coaxial relays, switches, and related accessories for applications in test and measurement, wireless communications, broadcasting, and defense. Tohtsu is renowned for its CX series miniature coaxial relays, which offer excellent high-frequency performance, low insertion loss, and high isolation, making them ideal for automated test equipment and RF signal routing. Other key product lines include the CX-800 series high-power relays, CX-350 series ultra-miniature relays, and various terminated and non-terminated RF switches. The company also offers a range of RF attenuators, coaxial connectors, and custom relay modules tailored to specific customer requirements. Tohtsu components are widely used in semiconductor test systems, network analyzers, spectrum analyzers, cellular base station testing, and satellite communication equipment. With decades of engineering expertise, Tohtsu has established a strong reputation for precision, reliability, and durability in demanding RF environments. While not a volume leader in the broader electronic components market, Tohtsu is considered a niche leader in high-frequency coaxial relays, with products specified by major test equipment manufacturers and communication system integrators worldwide. The company's commitment to quality and innovation has made its brand synonymous with high-performance RF switching solutions in the industry.