Clamp-on ferrite RFI filter for cables 3 to 5 mm in diameter. These filters fit perfectly on our speaker mic cables and TH-D7 cables, as well as the data cables for the Deluo and Garmin GPS 18 receivers.
Some handheld radios (certain older Icom models in particular) are vulnerable to RFI on their speaker mic cables when connected to a tracker, and can lock themselves in transmit mode if the cable is too close to the antenna. Installing one of these filters almost always fixes the problem.
For detailed specifications, see the manufacturer's data sheet: TDK ZCAT1325-0530A-BK