The 3in. GMC M10 Tank Destroyer, known unofficially as »Wolverine«, was based on the Medium Tank M4A2 and had an almost roofless turret. This allowed better visibility and easier servicing of the weapon, at an obvious cost of increased vulnerability.
The hull and turret on the M10 both took advantage of armor sloping, and both were fitted with bosses to which additional armor could be attached should the need have arisen.
The turret of the M10 was five-sided, including the gun shield in front.
On later versions, two triangular counterweights totaling 1600kg were added to the rear of the turret to balance the heavy 3" gun in the front thus greatly easing turret traverse.
52 M10 were delivered to Russia in 1944 under the Lend-Lease agreement.

Note : The vehicle shown here is of an early production series lacking the counterweights mentioned above. It's not known yet which version was actually delivered so the drawings are somewhat unproven at this point.