Many low-end gun safes are sold without any door sealing at all. That's bad. Door seals are very important...
:: First, a good door seal will keep out moist air, dramatically reducing the risk of rust forming on your firearms and personal articles.
:: Second, in order to resist the heat, smoke, and flames of a fire, your gun safe needs to have a tightly sealed door and the absolute minimum of external holes.
:: Security Products' safes utilize heat-activated sealing strips all the way around the door frame. In a fire, the seal will expand to eight times its normal size, blocking smoke and heat from entering the interior.