Finisar QSFP-40G-SR4 40GBASE-SR4 QSFP+ Transceiver — MPO-12, 850nm MMF, New Open Box
Warranty: Lifetime
Finisar 40GBASE-SR4 — parallel MMF / MPO, not BiDi duplex LC
Finisar QSFP-40G-SR4 — 40G QSFP+ SR4 transceiver, New Open Box
Manufacturer: Finisar (now Coherent)
Common PID / form: QSFP-40G-SR4 · FTL410QE-class 40GBASE-SR4
Description: Hot-pluggable QSFP+, 40GbE over parallel multimode fiber, MPO-12, 850 nm VCSEL
This is a Finisar 40G SR4 module — four 10G lanes over an MPO-12 ribbon for short-reach multimode links. It is New Open Box (unused module, packaging opened), distinct from any Cisco QSFP-40G-SR4 listing we carry. If your plant is duplex LC multimode and you expected BiDi, this is the wrong optic.
MSA QSFP+ / IEEE 802.3ba 40GBASE-SR4. Lifetime warranty from Resilient Tec.
Which One Do I Need?
| Going into | You need |
|---|---|
| 40G QSFP+ port, parallel OM3/OM4 with MPO-12, Finisar / MSA SR4 | Finisar QSFP-40G-SR4 — this product (New Open Box) |
| Same 40G SR4 optics, but you specifically need Cisco-coded OEM stock | Cisco QSFP-40G-SR4 (Refurbished) or Cisco QSFP-40G-SR4 (New) |
| Reuse existing duplex LC MMF (no MPO plant) for 40G | Cisco QSFP-40G-SR-BD BiDi — not SR4 |
| 100G parallel MMF instead of 40G | QSFP28-SR4-100G — different rate / cage generation |
MPO SR4 vs LC BiDi is the first fork at 40G multimode. SR4 needs 8 fibers (MPO). BiDi reuses two-strand duplex LC. Ordering SR4 for a duplex-LC-only closet is the most common wrong order on this family.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | QSFP-40G-SR4 (Finisar) |
| Form Factor | QSFP+ (hot-pluggable) |
| Ethernet Standard | IEEE 802.3ba 40GBASE-SR4 |
| Data Rate | 40 Gbps (4 × 10.3125 Gb/s); breakout to 4×10GBASE-SR supported on capable hosts |
| Wavelength | 850 nm (840–860 nm VCSEL) |
| Connector | MPO/MTP-12 (parallel MMF) |
| Fiber / Reach | 100 m OM3 · 150 m OM4 |
| DOM / DDM | Supported (Tx/Rx power monitoring typical) |
| Power | < 1–1.5 W class (Finisar Gen2/Gen4 SR4) |
| Operating Temperature | 0°C to 70°C (commercial) |
| Standards | QSFP+ MSA, IEEE 802.3ba, RoHS |
| Warranty | Lifetime, backed by Resilient Tec |
| Condition | New Open Box |
Note on Reach: OM3 100 m vs OM4 150 m
IEEE 40GBASE-SR4 rates 100 m on OM3 and 150 m on OM4. Extra MPO matings and poor end-face cleanliness eat margin fast on parallel optics — design to the fiber grade you actually have, not the headline number on the datasheet.
Good to Know
- New Open Box means unused hardware with opened retail/OEM packaging — not refurbished pull, not sealed retail new-in-box.
- This is Finisar, not Cisco. We also stock Cisco QSFP-40G-SR4 separately. Match coding to your platform matrix.
- Breakout to 4×10GBASE-SR is common on leaf/spine hosts that support it — confirm your switch supports fan-out before you order breakout harnesses.
- MPO polarity (Type B typically for SR4) and pinned vs unpinned must match your trunks.
Quick Checklist — Is This the Right Module?
You need 40GBASE-SR4 in a QSFP+ cage. Your fiber is parallel OM3/OM4 with MPO-12. Finisar / MSA coding is acceptable. You want New Open Box condition. You are not trying to reuse duplex LC BiDi plant.
Availability
In stock at Resilient Tec · Ships from Knoxville, TN.
Deep Finisar SR4 stock — ask for a kit quote if you are filling a row. Request a quote →
Warranty: lifetime, backed by Resilient Tec.
You Might Also Need
- Cisco QSFP-40G-SR4 — New
- Cisco QSFP-40G-SR4 — Refurbished
- Cisco QSFP-40G-SR-BD BiDi — Refurbished
- Arista QSFP-40G-SRBD BiDi — Refurbished
- Product guides · Request a quote
Related Guides
Lifetime warranty — how Resilient Tec backs what we sell
Finisar 40GBASE-SR4 — parallel MMF / MPO, not BiDi duplex LC
Finisar QSFP-40G-SR4 — 40G QSFP+ SR4 transceiver, New Open Box
Manufacturer: Finisar (now Coherent)
Common PID / form: QSFP-40G-SR4 · FTL410QE-class 40GBASE-SR4
Description: Hot-pluggable QSFP+, 40GbE over parallel multimode fiber, MPO-12, 850 nm VCSEL
This is a Finisar 40G SR4 module — four 10G lanes over an MPO-12 ribbon for short-reach multimode links. It is New Open Box (unused module, packaging opened), distinct from any Cisco QSFP-40G-SR4 listing we carry. If your plant is duplex LC multimode and you expected BiDi, this is the wrong optic.
MSA QSFP+ / IEEE 802.3ba 40GBASE-SR4. Lifetime warranty from Resilient Tec.
Which One Do I Need?
| Going into | You need |
|---|---|
| 40G QSFP+ port, parallel OM3/OM4 with MPO-12, Finisar / MSA SR4 | Finisar QSFP-40G-SR4 — this product (New Open Box) |
| Same 40G SR4 optics, but you specifically need Cisco-coded OEM stock | Cisco QSFP-40G-SR4 (Refurbished) or Cisco QSFP-40G-SR4 (New) |
| Reuse existing duplex LC MMF (no MPO plant) for 40G | Cisco QSFP-40G-SR-BD BiDi — not SR4 |
| 100G parallel MMF instead of 40G | QSFP28-SR4-100G — different rate / cage generation |
MPO SR4 vs LC BiDi is the first fork at 40G multimode. SR4 needs 8 fibers (MPO). BiDi reuses two-strand duplex LC. Ordering SR4 for a duplex-LC-only closet is the most common wrong order on this family.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | QSFP-40G-SR4 (Finisar) |
| Form Factor | QSFP+ (hot-pluggable) |
| Ethernet Standard | IEEE 802.3ba 40GBASE-SR4 |
| Data Rate | 40 Gbps (4 × 10.3125 Gb/s); breakout to 4×10GBASE-SR supported on capable hosts |
| Wavelength | 850 nm (840–860 nm VCSEL) |
| Connector | MPO/MTP-12 (parallel MMF) |
| Fiber / Reach | 100 m OM3 · 150 m OM4 |
| DOM / DDM | Supported (Tx/Rx power monitoring typical) |
| Power | < 1–1.5 W class (Finisar Gen2/Gen4 SR4) |
| Operating Temperature | 0°C to 70°C (commercial) |
| Standards | QSFP+ MSA, IEEE 802.3ba, RoHS |
| Warranty | Lifetime, backed by Resilient Tec |
| Condition | New Open Box |
Note on Reach: OM3 100 m vs OM4 150 m
IEEE 40GBASE-SR4 rates 100 m on OM3 and 150 m on OM4. Extra MPO matings and poor end-face cleanliness eat margin fast on parallel optics — design to the fiber grade you actually have, not the headline number on the datasheet.
Good to Know
- New Open Box means unused hardware with opened retail/OEM packaging — not refurbished pull, not sealed retail new-in-box.
- This is Finisar, not Cisco. We also stock Cisco QSFP-40G-SR4 separately. Match coding to your platform matrix.
- Breakout to 4×10GBASE-SR is common on leaf/spine hosts that support it — confirm your switch supports fan-out before you order breakout harnesses.
- MPO polarity (Type B typically for SR4) and pinned vs unpinned must match your trunks.
Quick Checklist — Is This the Right Module?
You need 40GBASE-SR4 in a QSFP+ cage. Your fiber is parallel OM3/OM4 with MPO-12. Finisar / MSA coding is acceptable. You want New Open Box condition. You are not trying to reuse duplex LC BiDi plant.
Availability
In stock at Resilient Tec · Ships from Knoxville, TN.
Deep Finisar SR4 stock — ask for a kit quote if you are filling a row. Request a quote →
Warranty: lifetime, backed by Resilient Tec.
You Might Also Need
- Cisco QSFP-40G-SR4 — New
- Cisco QSFP-40G-SR4 — Refurbished
- Cisco QSFP-40G-SR-BD BiDi — Refurbished
- Arista QSFP-40G-SRBD BiDi — Refurbished
- Product guides · Request a quote
Related Guides
Lifetime warranty — how Resilient Tec backs what we sell