This was the main Russian AA gun of 1920s and 30s and remained in use by both the Army and Navy until World War II. This gun was designed in the summer 1913 by engineer Tarnovski, but due to political infighting, Tarnovski was forced to sell his design to the Putilov factory where it was slightly modified by engineer Lender and was hence forth known by his name. Production started in August 1914 and twelve guns were produced during the first production lot. An additional twenty mounts with the elevation increased to +65 degrees were ordered by the Navy for delivery in July 1916, but none of these were actually delivered. The guns did not enter naval service until the Russian Civil War, but they were removed from ships almost immediately and then installed on trucks, armored trains and fixed land mountings.
Production was halted in 1921, but then restarted in 1922 and continued until 1934. In 1922, they received the official index 8-K, but they remained known as "Lender's Guns" during their service life. By World War II, this was an obsolete weapon, but several dozen were still used during the war.