The M3 x 12W7 JIS B1188 Phil Pan Split Washer Flat Washer Sems M/S Zinc is a type of washer that is used to distribute the load of a screw or bolt over a larger surface area. It is made of zinc-plated steel and has a split washer design that helps to prevent the screw or bolt from loosening. The washer has a diameter of 3mm and a thickness of 12mm. It is commonly used in automotive and industrial applications.