Headquartered in Chickasha, Oklahoma, HSI Sensing (Hermetic Switch, Inc.) is the innovative leader in the engineering and precision manufacturing of custom reed switch and sensor technology. The industry experts in solving problems for customers in challenging design applications, they also precision manufacture those solutions to ensure consistent, unmatched quality. All HSI products are made in the U.S.A.
 
Since 1968 HSI Sensing, an ISO 9001:2008 and AS9100 registered company, has been the premier choice for custom and standard reed switches, proximity sensors, and other sensing technologies for an array of industries including fluid control devices, reed relays, implantable medical devices, aerospace, heavy equipment, communications, transportation, and more. Their products are used in a variety of applications including commercial and military jet engines, security systems, commercial lawn mowers, external defibrillators, implantable medical devices, space station equipment, animal tracking, and more.