Question: The Schmalturm turret was a tank turret designed for use on the Panzer V Ausf, the Panther was a German medium tank deployed during which time period, on the Eastern and Western Fronts in Europe from mid-1943 to its end in 1945?
Context: The Medium Tank M1921 was a medium tank built in the United States in the inter-war period.  In design, it was similar to earlier WW1 era tanks.  United States Army engineers worked on the design of the tank, with some influence from British designs of the period, and from the earlier war experience.  One example was produced.  The tank was an early example of a turreted US tank, less usual at the time, with the turret housing the main gun, with the tank also possessing two machine guns for defence. The Panther was a German medium tank deployed during World War II on the Eastern and Western Fronts in Europe from mid-1943 to its end in 1945.  It had the ordnance inventory designation of Sd.Kfz.  171.  Until 27 February 1944, it was designated as the Panzerkampfwagen" V "Panther when Hitler ordered that the Roman numeral "V" be deleted.  Contemporary English language reports sometimes refer to it as the "Mark V". The Tigerfibel and Pantherfibel were crew instruction manuals for the German tanks of World War II, the Panzer VI Tiger heavy tank and the Panzer V Panther medium tank. The Type 5 medium tank Chi-Ri (五式中戦車 チリ , Go-shiki chusensha Chi-ri ) ("Imperial Year 2605 Medium Tank Model 9") was the ultimate medium tank developed by the Imperial Japanese Army in World War II.  Intended to be a heavier, more powerful version of Japan's sophisticated Type 4 Chi-To medium tank, in performance it was designed to surpass the US M4 Sherman medium tanks being fielded by the Allied forces.  A single prototype was incomplete when the war ended. Starting in 1938, the VK 20 series were the proposed replacements of the Panzer IV and Panzer III tanks with entries by MAN, Krupp and Daimler Benz.  It was initially projected to weigh 20 tonnes but grew to 24 tonnes.  By November 1941, the designs almost reached completion but against the professional judgement of Wa Pruef 6, political interference in December 1941 led to all of the designs being dropped.  The root of this adverse decision came from encounters with increasing numbers of T-34 and KV-1 tanks.  Reichsminister Fritz Todt declared that a new tank, 30 tons in weight should be designed and produced.  Oberst Fichtner argued that time would be lost developing this new 30 ton tank, the number produced would be reduced and engineer bridges could not support such a tank.  This new tank chosen from the VK 30 series would become the Panther, replacing the VK 20 series.  This decision would place the rushed MAN Panther into production as Germany's new standard medium tank, which was plagued with issues never fully addressed especially those caused by MAN's final drive.  It would also arrive too late, with Germany's position in a steep decline, having lost the initiative. The Type 89 medium tank I-Go (八九式中戦車　イ号 , Hachikyū-shiki chū-sensha I-gō ) was a medium tank used by the Imperial Japanese Army from 1932 to 1942 in combat operations of the Second Sino-Japanese War, at Khalkhin Gol against the Soviet Union, and in the Second World War.  The Type 89B model was the world's first mass-produced diesel engine tank.  The tank was armed with a short-barrel 57 mm cannon for knocking out pillboxes and masonry fortifications, and proved effective in campaigns in Manchuria and China, as the Chinese National Revolutionary Army had only three tank battalions to oppose them, which consisted primarily of Vickers export models, German Panzer Is, and Italian CV33 tankettes.  The Type 89 was a 1920s design medium tank, built to support the infantry, and thus lacked the armor or armament of 1940s generation Allied armor; and was regarded as obsolete by the time of the 1939 battles of Khalkhin Gol, against the Soviet Union.  The code designation "I-Go" comes from the "katakana" letter [イ] for “first” and the "kanji" [号] for "number".  The designation is also transliterated Chi-Ro and sometimes "Yi-Go". 100 56 TK or 100 TK ("100 mm, 56 length caliber, turret gun") is a Finnish stationary coastal artillery gun that utilizes the tank turret from the Soviet T-55 tank with its 100 mm D-10 tank gun.  100 56 TK was the main light weapon of the Finnish coastal artillery and complemented the medium gun 130 TK in the coastal artillery role until its decommissioning in 2012. Medium tank is a classification of tanks, particularly prevalent during World War II which represented a compromise between the mobility oriented light tanks and the protection and armour protection oriented heavy tanks.  The most widely produced, cost effective and successful tanks of World War II (the Soviet T-34, the American Sherman tank, the Japanese Type 97 and the German Panzer IV) were all medium tank designs, and the success of the concept would later lead to the development of later generations of medium tanks such as the Chieftain.  Many of the medium tanks lines became what are called main battle tank in most countries. The Schmalturm turret was a tank turret designed for use on the Panzer V Ausf.  B Panther II medium tank, Panther A and G medium tank, Panzer IV Ausf.  J medium tank and the VK 30.02 DB (a medium tank prototype).  The turret's shape resembled the Soviet T-34 tank turret.  It featured a narrow front to maximize protection while minimizing weight.  It was both lighter and easier-to-manufacture than the standard Panther turret.  The turret had a stereoscopic rangefinder with lenses on either side of the turret, located in spherical bulges.  No Schmalturms entered series production. The 503rd Heavy Panzer Battalion (abbreviated "s.Pz.Abt.  503") was a German heavy Panzer "Abteilung" (a battalion-sized unit) equipped with Tiger I tanks and Panzer IIIs.  In 1944, it was re-equipped with the new Tiger II.  The battalion saw action on the Eastern and Western Fronts during World War II.  As with other German Heavy Panzer Detachments, it was normally not assigned to a single corps, but shuffled around according to war circumstances.  Later the battalion became part of the newly formed Panzer Corps Feldherrnhalle as the Feldherrnhalle Heavy Tank Battalion.
Answer: World War II