Iphansi lingakwazi ukuzimela, livumelane nesibonisi sokuma kwesikhwama. Uziphu seal, uyasebenziseka kabusha. Impahla ephakathi yesikhwama ifilimu ye-polyester aluminizekisiwe, enenani elishibhile, ukubukeka okuhle nokusebenza okuhle kwesithiyo.