The 2827 from KR Electronics (A Division of NIC) is a Low Pass RF Filter with Frequency DC to 0.35 MHz, Stopband Frequency 400 KHz, 3 dB Cutoff Frequency 0.35 MHz, Lower Rejection 30 dB@400 KHz, Upper Rejection 1.5 dB@400 KHz. Tags: Module with Connector. More details for 2827 can be seen below.