The DR Series from K&L Microwave is a Band Pass Filter with Frequency 500 MHz to 3 GHz, Bandwidth 125 MHz, Center Frequency 1250 MHz, VSWR 1.50:1, Operating_Temperature -40 to 85 Degree C. Tags: Module with Connectors, Dielectric Resonator Filter, Ceramic Filter. More details for DR Series can be seen below.