Usually we buy air cushions online, and he will replace them for us. In fact, the replacement we are talking about is air cushion supplement. That is, after one of you has finished using it, don't throw that shell away, and you can continue to use it with a replacement. Expansion: replacement refers to the replacement of spare products with the same content as the formal products. General replacement is very common in air cushion BB cream and air cushion blush.