The rack model represents a physical two- or four-post equipment rack in which [devices](./device.md) can be installed. Each rack must be assigned to a [site](./site.md), and may optionally be assigned to a [location](./location.md) within that site. Racks can also be organized by user-defined functional roles. The name and facility ID of each rack within a location must be unique.
Rack height is measured in *rack units* (U); racks are commonly between 42U and 48U tall, but NetBox allows you to define racks of arbitrary height. A toggle is provided to indicate whether rack units are in ascending (from the ground up) or descending order.
Each rack is assigned a name and (optionally) a separate facility ID. This is helpful when leasing space in a data center your organization does not own: The facility will often assign a seemingly arbitrary ID to a rack (for example, "M204.313") whereas internally you refer to is simply as "R113." A unique serial number and asset tag may also be associated with each rack.
The [site](./site.md) to which the rack is assigned.
### Location
The [location](./location.md) within a site where the rack has been installed (optional).
### Name
The rack's name or identifier. Must be unique to the rack's location, if assigned.
### Status
Operational status.
!!! tip
Additional statuses may be defined by setting `Rack.status` under the [`FIELD_CHOICES`](../../configuration/data-validation.md#field_choices) configuration parameter.
### Role
The functional [role](./rackrole.md) fulfilled by the rack.
### Facility ID
An alternative identifier assigned to the rack e.g. by the facility operator. This is helpful for tracking datacenter rack designations in a colocation facility.
### Serial Number
The unique physical serial number assigned to this rack.
### Asset Tag
A unique, locally-administered label used to identify hardware resources.
### Type
A rack can be designated as one of the following types:
The canonical distance between the two vertical rails on a face. (This is typically 19 inches, however other standard widths exist.)
### Height
The height of the rack, measured in units.
### Outer Dimensions
The external width and depth of the rack can be tracked to aid in floorplan calculations. These measurements must be designated in either millimeters or inches.
If selected, the rack's elevation will display unit 1 at the top of the rack. (Most racks use asceneding numbering, with unit 1 assigned to the bottommost position.)
