Grade 1 Spring Hinges by Dynasty Hardware. 4 inch x 4 inch with 5/8" Radius Corners. Oil Rubbed Bronze Finish. Sold In Packs of 2 Hinges. Includes adjustment wrench and pins for adjusting the spring tension. Designed for Interior or Exterior These spring loaded hinges are recommended for use where an automatic self closing door is required. This four knuckle spring hinge is adjustable and the spring tension can be increased or decreased by using the included adjusting tool. These spring hinges are fully assembled and include all necessary screws. These spring hinges are UL rated and are approved for use on fire doors and are commonly used on garage doors to make sure they are full closed.