1. Metal joint box is made up of aluminum alloy, especially suitable for the protection of fiber cable joint under the high voltage electric field. 2. Metal joint box bears the excellence of high mechanical strength, good airproof performance, outstanding corrosion resistance and long service life. It can be used more than 25 years. 3. There are two models of metal joint boxes, one is to be mounted on poles and the other is to be mounted on towers.