If it idoesnt have a U or R rating its because its crap compared to
other types ... Its only bubble wrap, the true Radiant % is Foil,
Cheap foil. A simple test is hold it over a 100 watt bulb and feel the
warmth , now do that with 1" of foam, No warmth. Get an R value or its a
marketing ploy for the unedcated.