CRL Spring Latch is a simple device for holding screens into the window sill. Simply drill a 1/8" (3.2 mm) hole into the bottom of the screen frame and twist the spring into the opening. Drive the nail into the sill and slip the spring loop over the top of the nail and the screen will fit tightly against the sill. For small jobs or retail sales the spring latch is available in a package containing six springs and nails. 100 spring latches with nails per box.