US Energy Products 80 sqft (4ft x 20ft) White Double Bubble (XTEMP) Reflective Aluminum Insulation Roll Solid Metal Building Vapor Barrier - White Concrete Commercial Residential House Buildings

I was a little skeptical at first, but three rolls later, I don't feel so much as a draft in my camper, and it came two weeks early. During the winter, it's SILVER OUT to keep warm. In the summer, it's SILVER IN. Only thing is, you have to get GORILLA double sided tape to stick it up.

Works great for blocking heat through windows. Takes two layers to block all light though.

Probably the best deal for the money of any of these. Not flimsy or thin. Was easy to cut, easy to install and works perfect to insulate. Side effect, reduced noise by a bit.

Worked like it should