The QBF-2000-3800-50 from Qualwave is a Band Pass Filter with Frequency 2 to 3.8 GHz, Bandwidth 1800 MHz, Center Frequency 2900 MHz, Insertion Loss 1.7 dB, Upper Rejection 50 [email protected] to 5 GHz. Tags: Module with Connectors. More details for QBF-2000-3800-50 can be seen below.