One of the main goals of MBT designers is to design a vehicle in such a way to minimize weak zones in MBT's armor protection. These weak zones can be main gun mantle, main sight placed in not most fortunate place and such things. Leopard 2 is great example on how not fortunate placement of main sight increase front armor weak zone, of course it is not something tragic but still enough significant to make difference compared to other MBT's. Similiar main sight placement can be seen in Arjun Mk1 or Leclerc, however Leclerc have more complex main sight design and is is not so well visible from the outside. We can now compare such main sight placement with much more optimal design seen in many more design, where main sight goes out by turret roof opening that is much less risk design solution. (M1A1/M1A2) (Challenger 2 - prototype but there is not much difference between prototype and mass produced vehicle) So we can actually see how important is for overall vehicle protection, to minimize weak zones. Indian users will be especially interested in Arjun Mk1 turret design. We can see here 3 significant weak zones. 1) Main sight placement, similiar to that of Leopard 2, however picture is not clear enough to see details. 2) Wide main gun mantle. 3) Side turret is only partially protected by thick composite armor, the rest is protected only by thin RHA armor, thus still making vehicle highly vurnabale to hits within safe manouvering angles (frontal arc 60 degrees, so it is for right or left +/- 0 to 30 degrees from turret longitudinal axis). Otherwise tank is from the pure design point of view highly comparabale to Leopard 2 before KWS upgrades program. We also need to remember about turret bustle, it is not nececary but it would be good to protect bustle with the same thick composite armor as crew compartment. Leopard 2 as many other tanks (for example Arjun) have bustle protected only by thin RHA armor (probably spaced). This drawing shows that turret bustle in M1A1/M1A2 series have the same protection (by pure thickness) like the crew compartment side armor, Leopard 2 turret bustle have very weak protection, Challenger 2 turret bustle is also weak protected but covered by storage boxes.