The 2481 from KR Electronics (A Division of NIC) is a Band Pass Filter with Frequency 146.5 to 149.5 kHz, Bandwidth 3 KHz, Center Frequency 148 kHz, Insertion Loss 0.1 dB, Rejection 20 dB. Tags: Module with Connectors, Lumped Component Filter. More details for 2481 can be seen below.