Complex sentence: Many manufacturers are beginning to use copper alloys such as copper-magnesium (CuMg), which allow for smaller diameter wires with less weight and improved conductivity performance.
Split into simpler sentences: Many manufacturers are beginning to use wire from copper alloys such as Copper Magnesium, (CuMg). Alloys such as Copper Magnesium allow for smaller diameter wires with less weight and improved conductivity performance.