Four Post Rack The premium Panduit Four-post Rack System combines the stability of a cabinet with the accessibility of an open rack to provide the user with maximum flexibility when designing a data-center network layout. Four steel vertical posts and adjustable front and rear mounting rails provide the required strength and flexibility needed to work with various types of active equipment. Steel, 52 RU, 42in deep, Cage Nut Mounting Holes, Black, 1pc + hardware kit and paint piercing bonding kit.