Carrier question ??

[Garry Shipton (RIP)]

In order to get a better perspective on the real vehicle,I went out about six weeks ago ,bought and built the Tamiya kit of a Mark 2 carrier.The markings are from the 3rd Inf.Div,right out of the box.My question is what is the item,in the lower middle of the front,just right of the Bridge class sign.I put it on but the instructions don't say what it is !!