Dooble Action Spring Hinge 3", 4", 5" and Gray Finished Double Action Spring Hinge1, Available used for Euro Style Bar Door2, Allowing them to swing both ways and when they let go, they return to the closed position3, Maximum door thickness 1” – 1/4”, available in brass and gray.Size: 3” x 3” x 1.3 mm 4” x 4” x 1.4 mm 5” x 5” x 1.5 mm