Three different variants of Sherman Firefly served during the Second World War, each based on a different variant of the M4 Sherman. The Firefly conversion was carried out on Sherman I (M4), Sherman I Hybrid (M4 Composite) and Sherman V (M4A4) tanks. Some sources state that several Sherman IIs (M4A1) were converted and used in action, but photos allegedly showing these conversions are in fact views of the front half of Sherman I Hybrid Fireflies. To complicate matters, a very small number of Canadian licence-built Sherman IIs (M4A1), the Grizzly, were converted to Fireflies in Canada and used for training, but none saw action. The majority of Shermans converted were the Sherman V/M4A4 model, of which the British received about 7,200. The Sherman VC and IC variants are easily distinguished by their lower hulls; the VC having a lengthened hull, and a larger gaps between the suspension units. They employed the three-piece bolted transmission housing. The Sherman IC usually sported the cast transmission housing. The Hybrid can be distinguished by its upper hull, which is cast and gives it a distinctive curved look in comparison to the more boxy hull of a typical Sherman.