The 431D Series from Teledyne Relays is a RF Relay with Frequency 10 MHz to 1 GHz, Coil Voltage 5.0 to 45.0 V, Voltage 3.7 to 18.0 V (Pick-up Voltage), 0.15 to 10.4 V (Drop-out Voltage), Power 150 mW, Resistance 125 to 4000 Ohms. Tags: TO-5. More details for 431D Series can be seen below.