M4 Sherman Jumbo
The "Jumbo" Sherman is a heavy variant of the standard M4A4 Sherman.
Designed to assault fortifications, the M4 "Jumbo Sherman" featured increased frontal armor (thicker even than the German Tiger I) in order to withstand fire as it battered through defensive lines. Although a few (~30 total) were rearmed in the field with the 76 mm gun, the majority of the 254 tanks built retained the lower-velocity 75mm in light of its more powerful high-explosive charge. Jumbo Shermans were often deployed in two-tank sections to reinforce their thinner-skinned brethren.
Although its heavier frontal armor offers more protection against fire, the Jumbo Sherman is slower than its standard counterpart and ill-suited to dealing with enemy tanks. It is best employed to blast through enemy defenses and provide a hole for medium tanks and infantry to exploit the breakthrough.