attain a speed of . Some vehicles were equipped with two searchlights for night operations and Type 94 Mk 4 Otsu radios (this 1934 model had a range of 0.6 mile and weighed 88 lb; it used a long antenna of "reverse L" shape). The original suspension with six road wheels and three return rollers caused ongoing problems and it was redesigned. The later production series had four road wheels and two return rollers. The later version has sometime been mistakenly referred to as a "Type 93 light tank". The Type 92 was eventually replaced by the Type 94 tankette during the Second Sino-Japanese War, although both British and American sources often confused the two models. Armor and armament The Type 92 used riveted and welded armor with a maximum thickness from 6 mm (in the hull) to 12 mm (in the turret). The thin armor kept the weight to three tons; however, it could be penetrated by machine gun fire. Although its armor was thinner and its weaponry much lighter than its European contemporaries, the Type 92 was only able to reach a speed of 40 km/h. The armament consisted of two machine guns, one in the manually traversed turret and one in the hull. Early models had 6.5 mm Type 91 machine guns in both positions. Later, the hull-mounted weapon was replaced with a manually aimed 13 mm Type 92 heavy machine gun, license-built from Hotchkiss. The weapon had limited traverse, but included a pivoting eyepiece on the gunsight optics and a high-angle mount, allowing anti-aircraft use. The turret machine gun was replaced later by the 7.7 mm Type 97 light machine gun. After production ended, efforts were made to improve the armament to keep the vehicle relevant on the battlefield. Attempts were also made in 1933 to mount a 37 mm tank gun in the hull of the vehicle to give it "anti-tank capabilities". It was determined to be "impractical" and therefore abandoned. The Type 98 20 mm machine cannon was successfully mounted on the hull of a number of the vehicles after 1937, in place of the 13.2 mm machine gun. In addition, an external anti-aircraft mount was stowed in the vehicle, which could be attached to the outer rear facing of the turret, allowing an additional Type 91 machine gun to be mounted. The engine hatches could be opened and locked together to form a