The Swanson Speed Square was first developed by company founder Albert Swanson in 1925. This innovative tool combines 5 tools into 1- 1. Try Square, 2. Miter Square, 3. saw guide, 4. line scriber, and 5. protractor. The Speed Square is die-cast for durability and accuracy. Made of heavy-gauge aerospace aluminum alloy, it is built to last. Black-filled gradations stand out against a matte finish for easy reading. Look for the Diamond cutout for genuine Swanson products.