The Wasserfall was to be the first guided "Surface-to-Air Missile", According to Albert Speer and Carl Krauch it could have devastated the Allied bomber fleets. The project enjoyed little support in its earlier stages. Speer, later claimed that with the use of uncompromising use of jet fighters, and Wasserfalls as air defense, it would have essentially stalled the allied bombing offensive.
(Bundesarchiv Bild 141-1898)

Th Father of Guided Surface-to-Air Missile

Crew of a PaK 43, doing what appears to be a crew exercise, Southren front, Ukraine, December 1943.
(Bundesarchiv Bild 101I-708-0262-20A)

PaK 43 in Ukraine

A 17cm Kanone 18 with Mörserlafette chassis, firing at allied positions, Italy, February 1944.
(Bundesarchiv Bild 101I-310-0895-13A)