Commercial grade aluminum threshold assures years ofprotection from the elements. Installing a threshold will help to seal outdrafts from the bottom of your door. A door sweep is recommended to be usedwith this threshold to create a weather tight seal. ADA approved From theManufacturer Commercial grade aluminum threshold assures years of protectionfrom the elements. Installing a threshold will help to seal out drafts fromthe bottom of your door. A door sweep is recommended to be used with thisthreshold to create a weather tight seal. ADA approved