Panduit FHS9N-24-LAR 24-Fiber OS2 APC HD Flex LC Duplex Fiber Cassette
Overview
The Panduit FHS9N-24-LAR is a 24-fiber, OS2 single-mode fiber cassette built on Panduit's HD Flex platform — designed for high-density structured cabling environments where port count, low insertion loss, and long-haul signal integrity matter. With 12 LC duplex ports on the front and unterminated pigtails on the rear, this cassette fits into fiber optic cassette enclosures supporting modular, field-reconfigurable patch architectures in data centers, enterprise backbones, and campus distribution frames. The APC (angled physical contact) polish on the LC connectors targets OS2 single-mode runs where back-reflection must be kept below -60 dB — critical for DWDM, coherent optics, and active equipment that is sensitive to reflected light. If you are deploying standard UPC connectors on a mixed-mode plant, look at other cassettes in the Panduit fiber optic systems line instead.
Key Features
- 24-Fiber OS2 Single-Mode (9/125 µm): OS2 glass supports runs well beyond 10 km at 10G and is the correct choice for inter-building or campus backbone segments. Specifying OS2 here future-proofs the link for 40G/100G wavelength-division applications without re-pulling cable.
- APC Polish on LC Duplex Ports: The angled ferrule on each of the 12 LC duplex ports reduces back-reflection to levels required by DWDM and laser-based transceivers. Mixing APC and UPC connectors will cause a visible connector mismatch (green vs. blue ferrule) and elevated IL — do not mix in the same link.
- 12 Front Ports (HD Flex Form Factor): Twelve LC duplex ports terminate all 24 fibers in a single cassette slot. In a 1U HD Flex panel, multiple cassettes can be populated to achieve 144 fibers per rack unit — a meaningful density advantage in space-constrained fiber optic panels and enclosures.
- Unterminated Rear (Splice or Field-Terminate): The rear pigtails are unterminated, giving installers the choice of fusion splicing directly to the backbone cable or field-terminating to a connector type of their choosing. This is the correct configuration when the backbone fiber count or connector type at the cable end is not yet finalized.
- Polycarbonate Housing: The black polycarbonate shell is lightweight and provides adequate mechanical protection in a properly closed enclosure. This is an indoor-rated component — it is not designed for direct outdoor or harsh-environment exposure without an appropriate hardened enclosure.
- Standard Insertion Loss (Standard IL): The cassette is rated at standard IL, not low-IL or ultra-low-IL. For loss-budget-sensitive links running near the margin of a 10G or 40G link, verify your total link loss budget accounts for the connector IL at each mated pair before specifying this cassette.
Integration and Compatibility
The FHS9N-24-LAR (often searched as FHS9N 24 LAR) is designed for Panduit HD Flex enclosures and panels. Before ordering, confirm your enclosure accepts HD Flex cassette modules — legacy Panduit HS or non-HD enclosures use a different cassette form factor and the cassette will not seat or lock correctly. The LC APC front ports mate with LC APC patch cords only; confirm all patch cords in the link are APC-polished to avoid elevated insertion loss and back-reflection. For guidance on structured cabling architecture, the fiber optic cabling planning guide covers OS1 vs. OS2 selection, loss budget calculation, and cassette-based vs. panel-based designs. Sold individually; carton quantity is 10 units for volume orders.
What's in the Box
- 1x Panduit FHS9N-24-LAR HD Flex 24-fiber OS2 APC LC duplex fiber cassette
Frequently Asked Questions
Q: What enclosures is the FHS9N-24-LAR compatible with?
A: The FHS9N-24-LAR is designed for Panduit HD Flex enclosures and panels. It is not compatible with legacy Panduit HS-series or non-HD Flex enclosures — confirm your enclosure accepts HD Flex cassette modules before ordering.
Q: Can I use standard UPC LC patch cords with the FHS9N-24-LAR?
A: No. The front ports are APC-polished (angled physical contact). Mating an APC ferrule with a UPC ferrule will cause elevated insertion loss and poor back-reflection performance. Use only LC APC patch cords throughout the link.
Q: How many fibers does the FHS9N-24-LAR support?
A: The cassette supports 24 fibers, terminated to 12 LC duplex ports on the front. The rear pigtails are unterminated (9/125 µm OS2).
Q: Is the FHS9N-24-LAR suitable for outdoor or harsh-environment installations?
A: No. The polycarbonate housing is rated for indoor structured cabling environments. For outdoor or harsh-environment deployments, house the cassette inside an appropriate hardened enclosure rated for those conditions.
Q: What is the fiber diameter of the FHS9N-24-LAR?
A: The fiber diameter is 9 µm (9/125 µm single-mode OS2), appropriate for long-haul and campus backbone applications.
The FHS9N-24-LAR is one of those cassettes I specifically call out when a customer is running OS2 backbone to equipment with DWDM transceivers or any laser source sensitive to back-reflection. The APC polish is the detail that matters here — standard UPC cassettes are perfectly fine for most enterprise runs, but once you are feeding coherent optics or DWDM multiplexers, APC is not optional, and this cassette is built for exactly that use case.
Technical Highlights:
- APC Polish (12 LC Duplex Ports): Angled ferrules keep back-reflection below the -60 dB threshold required by most coherent and DWDM transceivers — a spec that standard UPC connectors at roughly -50 dB simply cannot meet.
- 24 Fibers / HD Flex Form Factor: All 24 OS2 fibers terminate in a single cassette slot. In a fully populated HD Flex 1U panel this translates to very high fiber density per rack unit, which matters in any MDA or HDA where rack space is measured carefully.
- Unterminated Rear Pigtails: Leaving the rear unterminated is the right call for a backbone cassette — fusion splice directly to the cable plant once pulled, and you eliminate a connector pair (and its IL contribution) from the link budget entirely.
Deployment Considerations:
- Verify your HD Flex enclosure revision accepts this cassette form factor before installation — Panduit has released multiple HD Flex generations and not all cassettes are cross-compatible with all enclosure vintages.
- Standard IL rating means this cassette is not the right pick for links already near the edge of a 10G or 40G loss budget — in those cases, specify a low-IL variant and verify the full end-to-end loss calculation before committing to the cassette model.
The FHS9N-24-LAR is the right specification for campus backbone termination points feeding coherent optics, DWDM systems, or any active equipment where back-reflection tolerance is a hard requirement — not a general-purpose cassette swap for everyday enterprise fiber runs.
