FS: Kenwood/Trio model YK-88C 500 Hz CW filter, good condition and
works very well. This is the optional CW filter that goes in just
about every Kenwood transceiver, such as models # TS-440, 450, 430,
120, 130, 530, 660, 830, 930, 570, 850S, 950S and many others. Current
new price at the ham stores is $129.95, this one is $75 plus postage.