From CyberWurx Customer Wiki

Dell 4220

Dell PowerEdge Rack Server Cabinet 42U

External Dimensions:

 . 1999mm tall
 . 750mm wide
 . 1071mm deep

Interior Rack Dimesions:

 . 19 inches between right and left posts
 . 28 inches between front and rear posts
 . Non-threaded square-holed rack

Features:

• Designed around maximizing airflow while maintaining security.
• Both front and rear (dual) doors lock via key.
• Doors 80% perforated to ensure maximum airflow.
• Built-in cable management and PDU mounting systems ensure power and network cable management have minimal impact on airflow.