770-BBBR: Dell 2U Cable Management Arm (CMA) for ReadyRails II
Also listed as: 0W764K, W764K
The Dell 770-BBBR is a Dell 2U Cable Management Arm (CMA) for ReadyRails II providing tool-less rack mounting and maintenance sliding access for Dell PowerEdge R740, R740XD, R750, R760 servers.
Specifications
| Part number | 770-BBBR |
|---|---|
| Brand | Dell |
| Type | Rail kits |
| Other numbers | 0W764K, W764K |
| Status | current |
| Form factor | 2U Articulated Cable Management Arm |
| Cable capacity | Supports high-density power, SAS, and multi-port network cables |
| Attachment type | Tool-less snap-in latching to ReadyRails II outer and inner rails |
| Reversible | Can be mounted on the left or right side of the rack |
About the 770-BBBR
The Dell 770-BBBR is a Dell 2U Cable Management Arm (CMA) for ReadyRails II engineered to mount Dell PowerEdge servers into standard 19-inch equipment racks. Built with heavy-gauge steel ball-bearing sliding mechanisms or static brackets, the 770-BBBR provides tool-less installation into square-hole or unthreaded round-hole four-post server racks.
Compatibility
Designed for Dell PowerEdge R740, R740XD, R750, R760 servers, the 770-BBBR accommodates standard rack depths and integrates with optional cable management arms. The 770-BBBR supports square-hole and round-hole racks using Dell ReadyRails mounting brackets, and can adapt to threaded four-post racks with optional adapter kits.
How to identify a genuine unit
Genuine Dell 770-BBBR rail assemblies carry stamped part numbers including DP/N 0W764K, Left/Right rail indicators (L/R), and rack depth adjustment markings. Quick-release blue latch buttons on the 770-BBBR facilitate tool-free installation and removal from equipment rack posts.
Buying used
When purchasing pre-owned 770-BBBR rails, inspect the inner and outer sliding tracks to ensure ball bearings glide smoothly without binding or missing ball cages. Verify that both front and rear spring-loaded latch pins on the 770-BBBR engage securely, and confirm that both left and right rail assemblies are included.
Fits these models
- Dell PowerEdge R740
- Dell PowerEdge R740xd
- Dell PowerEdge R750
- Dell PowerEdge R760
- Dell PowerEdge R540
- Dell PowerEdge R550
Equivalent part numbers
- Dell W764K Dell direct spare part number for 2U Cable Management Arm
FAQ
Can the CMA be detached quickly for server removal?
Yes, quick-release buttons on the mounting brackets allow rapid tool-less detachment from the sliding rails.
Does the CMA impede rear airflow in high-density racks?
Properly routed cabling through the CMA maintains designed exhaust airflow, though dense high-TDP setups may monitor rear temperature delta.
Buying or selling 770-BBBR?
New, refurbished or used. Tell us the quantity and condition and we connect you with a vetted reseller in your region, usually within one working day.
Sources
- Dell 2U Cable Management Arm Guide, checked 2026-10-27