Prime-Line PL 14630 Corner Mount Flat Window Spring &ndash; Holds Window Screens Into Sliding Aluminum Channels, 2-3/4&rdquo;, Pack of 25 HOLD SCREENS IN PLACE - Use these corner mount flat window springs to hold window screens into aluminum channels. This pack of 25 springs is great to keep on hand! REPLACEMENT PART  If your window screen isnt staying put, dont buy a whole new window! Instead, use these window screen springs to replace the part and keep the screens where they belong. DURABLE  These steel tension springs are heat-treated, zinc plated and mill finished, so they are strong, durable and made to last. EASY INSTALLATION  Installation is quick and easy and no tools are required! This corner mount flat window spring slides into the corner of 3/8 or 7/16 frame. SIZING  This corner mount flat window spring measures  W x 2-3/4 L and slips into the corner of a 3/8 or 7/16 thick frame.