It was for the top of the awning to slide into, i will try take a pic when i get chance nd send it to you. The side have thick cushion and are pegged down taught, you can get extra rear poles to give additional support if needed. There are storm straps also which we have for ours and you'll need a rear skirt which we are still working on to make it dog proof and your welcome as its nice to talk with people in the uk that have the same type of camper as us