As a single-sided heat sealing film, UCF-AF product is an anti-fogging film consisting of three layers and used to package a product whose freshness should be kept. Temperature differences between inside and outside and metabolic cycles of contents in the UCF-AF films prevent water from being contents inside the package. This mechanism makes it easier to identify the contents and their freshness inside so that it can boost sales. Another benefit is that it can extend the shelf life of a product.