Whilst I’ve used the tent in very heavy rain out with issue without this cover (due to the cover being out of stock) and no water got in, I consider this cover essential. It does indeed dramatically reduce temperatures inside the tent on a sunny day. It also further darkens the bedrooms at the back, which helps sleep ins. Cover attaches silver side down, and clips on around the tent. Logo at the back. The left edge of the cover has non adjustable hooks, hook those onto the tent first then do the back and right side and then front. Doesn’t take long. The right hand side hooks are adjustable. That’s one of the nicest things, it doesn’t need guy ropes or tie lines, it just clips into fabric hooks already on the tent. Is it overpriced? Maybe. Should it be included? Maybe. Is it worth having? Absolutely.