The TO-5 relay, originally conceived and developed by Teledyne, has become one of the industry standards for low-level switching from dry circuit to 1 A. Designed for high-density PC board mounting, these TO-5 relays are some of the most versatile ultraminiature relays available because of their small size and low coil power dissipation. The H Series high-temperature TO-5 relays are designed for reliable operation in elevated ambient temperatures up to 200 °C. Special material selection and processing provide assurance of freedom from contact contamination and mechanical malfunctioning that might otherwise be caused by ultra high ambient temperature conditions. By virtue of its inherently low intercontact capacitance and contact circuit losses, the H Series relays have proven to be excellent ultraminiature RF switches for applications with frequency ranges well into the UHF spectrum.