The 3MB/C-21.4/T0.4-A1 from Sainty-Tech Communications Limited is a Band Pass Filter with Frequency 21.16 to 21.64 MHz, Bandwidth 0.48 MHz (3dB), Center Frequency 21.4 MHz, Insertion Loss 6.28 dB, Upper Rejection 40 dB. Tags: Lumped Component Filter. More details for 3MB/C-21.4/T0.4-A1 can be seen below.