The 421D Series from Teledyne Relays is a RF Relay with Frequency 10 MHz to 1 GHz, Coil Voltage 5.0 to 32.0 V, Voltage 3.7 to 18.0 V (Set/Reset Voltage), Power 290 mW, Resistance 61 to 2000 Ohms. Tags: TO-5. More details for 421D Series can be seen below.