The 2258 from KR Electronics Inc is a Low Pass RF Filter with Frequency DC to 1.2 MHz, Stopband Frequency 1.32 MHz, 3 dB Cutoff Frequency 1.2 MHz, Lower Rejection 60 dB@1.32 MHz, Upper Rejection 3 dB@1.32 MHz. Tags: Plug In. More details for 2258 can be seen below.