The QBF-2100-3800-50 from Qualwave is a Band Pass Filter with Frequency 2.1 to 3.8 GHz, Bandwidth 1700 MHz, Center Frequency 2950 MHz, Insertion Loss 1.5 dB, Upper Rejection 50 [email protected] GHz. Tags: Module with Connectors. More details for QBF-2100-3800-50 can be seen below.