Some type of reflective blanket maybe? Insulation? Debris from a re-entry capsule? Weird therapy thing? Appx 3 foot wide, by maybe 4 tall. Has some ‘bulk’ but not much – maybe 5 pounds. Back side is grey vinyl. Found in a “Bargain Bins” place, but cant match with anything on Amazon…

A: Hey, I know this one! It’s a grill blanket. It’s for more of a smoker/barrel shaped grill (Traeger is a popular brand). The handle of the grill lid fits into that slot and the straps come around to the front to fully wrap around the grill body. Conserves heat a lot better, especially in the colder months.