This is a German World War I bakelite Soap box with K.A. (= Kriegsausschuss-) Seife.
This rough greyish type of soap was issued to german soldiers between 1915 and 1918.
The dimensions of the box are 9 x 3 x 6,5 centimeters.
A neat personal item, great for diaplay or to add to a WWI german personal breadbag.