SizeYou will receive 1 roll of bubble reflective foil insulation, measuring 16 in x 10 Ft/40cm x 3Meter(W*L), 3mm thick, enough length can be used for a long time. Energy SavingReflective aluminum foil is composed of upper and lower aluminum foil and a single layer of polyethylene bubbles in the middle. The surface aluminum film can directly reflect rays and heat, and the bottom aluminum blocks residual heat. It has double-layer protection and a better heat insulation effect. It can be insulated cold air to create a hot winter and block heat to create cooler summers, thus saving your electricity bill.More Than 80% Thermal InsulationDouble-layer bubble reflective film has a thermal insulation effect of more than 80%, and a thermal conductivity of 0.032-0.036W/m.K.