Are there windows in your home that have missing or damaged screens and frames? Don’t rush out to buy pricey new ones when you can easily make your own! Prime-Line Aluminum Screen Frame comes with 20 pieces constructed from 0.020 inch thick aluminum, measures 72 inch in length and features a durable aluminum finish. Use with Prime-Line MP7729 5/16 inch x 3/4 inch square cut plastic corners to create high quality and easy to assemble window screens. The lineal pieces of the high-quality aluminum screen frame material are intentionally cambered (curved) outward, designed to prevent inward bowing when screen cloth is installed and stretched taut. With the quality aluminum frame materials, screens can easily be made with your choice of materials, including a solar screen fabric to create effective and energy-efficient sun screens. Prime-Line aluminum screen frames are constructed with a thicker spline channel for added support. Recommended spline sizes: 0.185 inch for standard fiberglass cloth, 0.165 inch for aluminum screen and 0.155 inch for solar screen and pet screen. For screens over 48 inch in height or width, a spreader bar is recommended in combination with spreader bar clips to prevent the screen from bowing in (Prime-Line items MP14138 and MP7794).