1U Server Chassis – Slim Rackmount Enclosures | Server Warehouse

Our 1U chassis range covers two distinct use cases. The K125L is a compact 250mm deep Mini-ITX chassis for network appliances, firewalls and lightweight edge deployments where rack depth is limited. The K155F is a full-depth 550mm ATX chassis with four 3.5-inch drive bays, suited to builds that need a full-size ATX motherboard in a 1U footprint.

1U is the most space-efficient rackmount form factor at 44.45mm high, but it comes with trade-offs: cooling is tighter, expansion slots are typically limited to one low-profile card, and you will need a 1U-specific power supply. Standard ATX PSUs do not fit. Our DH-1U-700P (600W) and DH-1U-320P (200W continuous / 320W peak) are compatible options.

Both 1U chassis are sold without rail kits. The NJ-2020-18 18-inch rail kit is the correct option for the K125L in shallow racks. For full-depth installations, the OCR4526 26-inch rail kit is appropriate for the K155F.