Emtek Heavy Duty 9600 Solid Brass Hinges with Ball BearingsMade from Solid Brass Heavy Duty Hinges: Built to handle substantial weight and high traffic. Commonly used in commercial and industrial settings where doors are larger, thicker, and subjected to constant use and abuse. Ball Bearing Hinges: Feature ball bearings within the hinge knuckles. These bearings reduce friction and create a smoother and more durable pivot point for the hinge, allowing for easier door movement but can come at a premium