The MFJ-918 1:1 Current Balun was designed to replace the center insulator of a dipole antenna. It is made up of 50 Ferrite Core Beads placed onto a 13-inch piece of RG-303 Coax. Operates 1.8 to 30 MHz. The coax and SO-239 connectors have Teflon(R) for maximum insulation and extended life of the product. The MFJ 1:1 Current Balun is enclosed in schedule 40 PVC pipe for maximum strength and protection. Unlike other baluns, the MFJ-918 makes a direct electrical connection to the antenna with #14 copper wire. The MFJ Current Balun will reduce or eliminate stray RF often found on coax. This stray RF can cause burns and other problems with electronic equipment in ham-shacks and vehicles. Stray RF also results in a loss of radiated power from the antenna, which will lead to a great reduction in signal strength.