Sold as a set of 2, these cage hole rails offer a secure and easy way to install and mount shelves and other accessories into your high density wall cabinet. Our mounting rails are offered in 4 heights: 12U, 15U, 18U and 25U to suit your specific high density wall cabinet with it’s corresponding height. This item features standard EIA compliant 1.75” RU spacing, marked and numbered on rails and is universally compatible with our M6, 10- 2 or 12-24 cage nuts and mounting screws for ease of installation.