Our traditional "Bartholomew" Screw Out Sash Stop in our Sash Heritage range is fitted to the top Sash to restrict the bottom sash from passsing. The Sash Stop can be retracted with a screw driver to allow the window to open.Complete with matching screwsAvailable finishes: Antique Brass, Polished Chrome, Polished Brass & Satin ChromePlease note: When fitting YOU MUST pre drill the screw holes or use a similar sized pozi screw to make the thread of the screw in the window first. Then carefully tighten the screw with a HAND screwdriver.