IEDs are nasty, I'm not sure of the type that got one of our Challies, I imagine that it's hush-hush. Probably not a 155mm though, because scuttlebutt has it that the same area on the Challie was penetrated by an RPG-29 a few months before the IED incident. Either way, we've painted over that hole now.
Looks like we also might use ERA as well, judging by the make-up of this Challenger II.
And then of course there's the grills at the back against RPGs (great idea by the way chaps, thanks for that, I think it was the US that came up with that one first?).