The DF3R3-506M72 from Innertron is a Band Pass Filter with Frequency 470 to 542 MHz, Center Frequency 506 MHz, Insertion Loss 2.5 dB, Rejection 20 to 30 dB@ 356 to 656 MHz, Ripple 1 dB. Tags: Surface Mount. More details for DF3R3-506M72 can be seen below.