The standard ML500 valve has M6 threaded ports and at most one input and one output. These specialty valves are designed to use ¼-28 threaded tubes and come in distribution options of 2, 3, 4, and 8 ports. The 3, 4, and 8 port valves are made with a ceramic fluid path instead of the standard PTFE valve plug. The ceramic offers superior performance when used with salt solutions that are likely to crystalize and cause leaks.