The 2826 from KR Electronics (A Division of NIC) is a Low Pass RF Filter with Frequency DC to 45 kHz, Stopband Frequency 50 KHz, 3 dB Cutoff Frequency 45 kHz, Lower Rejection 30 dB@50 KHz, Upper Rejection 1.5 dB@50 KHz. Tags: Module with Connector. More details for 2826 can be seen below.