HPE 868858-B21 Apollo Server Tray I/O Module Option Kit

• Brand: HPE
• SKU / Option Part Number: 868858-B21
• Official Product Name: HPE Apollo Server Tray I/O Module Option Kit
• Product Type: I/O module option kit
• Platform Family: HPE Apollo
• Documented Server: HPE ProLiant XL230k Gen10
• Primary Function: Enables supported server-tray I/O configurations
• External PCIe Riser: Dependency Required for documented XL230k Gen10 external PCIe riser options
• Related Riser Options: 866720-B21, 866721-B21, 866722-B21
• PCIe Riser Types Referenced: x16 Low Profile External; x8 Low Profile Internal/External; x8 Low Profile Internal
• Mezzanine B Impact: Internal Mezzanine B slot unavailable with the applicable PCIe options
• Compatibility: HPE Apollo server tray; specifically documented with XL230k Gen10
• PCIe Interface: Not the specification of this kit; PCIe characteristics apply to the associated riser
• Network Ports: Not specified for this option kit
• Storage Controller: Not included
• Memory: Not included
• Power Supply: Not included
• Primary Deployment: Apollo server-tray I/O expansion

Why Choose This Product?

• Corrects the configuration dependency – This is not simply a generic server accessory; HPE identifies 868858-B21 as the Apollo Server Tray I/O Module Option Kit required for supported external PCIe riser configurations.
• Enables documented PCIe expansion – Buyers deploying supported XL230k Gen10 external PCIe risers need this module option, making it an important component of the complete configuration. 
• Purpose-built for HPE Apollo infrastructure – Provides a manufacturer-specific option instead of relying on an unverified third-party or generic I/O component.
• Improves procurement accuracy – SKU 868858-B21 gives purchasing teams a precise reference for quotes, BOMs, inventory systems, and replacement sourcing.
• Supports scalable I/O planning – When paired with the appropriate HPE PCIe riser, the module supports more flexible I/O configurations for demanding Apollo deployments.
• Helps prevent incompatible purchases – The documented relationship between the I/O module and external PCIe risers makes configuration validation easier before purchase.
• Important slot-planning visibility – HPE documents the loss of Internal Mezzanine B availability with the relevant PCIe options, allowing engineers to plan I/O resources accurately. 
• Suitable for enterprise and HPC infrastructure – Its role in Apollo server-tray PCIe expansion makes it relevant to data-center environments where accelerator, high-speed I/O, and specialized PCIe configurations are required.