The M 103 unit (Allied designation M Mk IX) was the same as the M 101, except that it responded to either a RED or a BLUE field. Work on this unit began in the summer of 1940 and was completed and ready for operational use in the spring of 1941. It was used alone or in combination in the BM 1000 I/II mine cases. Like that the M 101, the M 103 used an electrical, eight-plase P.D.M.

Figure 162 – M 103 Unit – Front and Side Views