 The Type 1 37 mm AT Gun was available only in limited quantities, and the additional barrel length provided for only an incremental improvement in performance over the more numerous Type 94 37 mm AT gun.It was marginally effective against the Allied M3 Stuart light tank in the Pacific War, but not against the M4 Sherman which was soon fielded in large numbers by the Allies.It was fielded in a wide variety of areas, but most notably Southeast Asia, and continued to be used with diminishing effectiveness until the end of World War II.