Jamb spreaders enable you to spread a vinyl jamb pocket in order to replace balances,pivot shoes or other components  without the need to cut into the jamb or melting the vinyl with  hot air gun. Includes TWO jamb stretchers.Jaws are made of 6061-T6 Aluminum. Tighten and loose by hand only. Designed for vinyl jambs only. Easy to use. Makes job fast and neat. Manufactured & Assembled in USA  NOTE : Jaws are 1/2" when fully closed, if your window is under 1/2" contact us before purchase and we can modify jaws to fit your application.