Network rack, High density rack, Open frame rack

The High Density Network Rack (HDNR) system is an innovative open-frame rack solution with a full line of rack, cable management, power and airflow accessories.  The HDNR is able to provide adjustable in-rack cable management, equipment mounting rails and airflow accessories to deliver industry-leading flexibility, density and reliable mounting of critical network equipment. 

Tripp Lite 42U 4-Post Open Frame Rack Cabinet 36-inch Depth No Sides or Doors rack - 42U

Data Center Server Rack Wiki: Definition, Types and Buying Guide

Heavy-Duty 4-Post Open Frame Server Rack, 48U

Open Rack Systems

Lenovo 42U and 48U Heavy Duty Rack Cabinets Product Guide > Lenovo Press

Data Center Racks, Cabinets, and Cages: An In-Depth Guide - Dgtl Infra

24U Server Racks - CR4824

Accu-Insider Open-frame rack

Two-Post Racks Chatsworth Products