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Arista QSFP-40G-ER4 40GBASE-ER4 QSFP+ 40 km SMF
40 Gbps 40GBASE-ER4 QSFP+ transceiver, 4 lambda WDM, 1310 nm band, up to 40 km SMF, 0 to 70 °C case temperature.
- Manufacturer
- Arista Networks, Inc.
- Mfr part number
- QSFP-40G-ER4
- Series
- 40G QSFP+
- Category
- Fiber optic transceiver modules
- Datasheet
- QSFP-40G-ER4 datasheet (PDF)
QSFP-40G-ER4 specifications
| Attribute | Value |
|---|---|
| Part Number | QSFP-40G-ER4 |
| Manufacturer | Arista Networks, Inc. |
| Brand | Arista Networks |
| Standard | 40GBASE-ER4 |
| Form Factor | QSFP+, hot-swappable |
| Data Rate | 40 Gbps |
| Wavelength | 4 lambda WDM, 1310 nm band |
| Media | Duplex single-mode (G.652) |
| Max Distance | 40 km SMF |
| Connector | Duplex LC |
| Tx Power | −2.7 to +3.8 dBm/lane |
| Rx Power | −21.2 to −4.5 dBm/lane |
| Max Power | 3.5 W |
| Case Temp | 0 °C to 70 °C |
| Dimensions | 13.5 × 18.4 × 72.4 mm |
| Reach detail | 40 km on duplex single-mode fiber (engineered link beyond 30 km) |
All values are from Arista Networks' published Optics Modules and Cables data sheet (Sep 2026). Confirm platform support for your switch with us before ordering.
About the Arista QSFP-40G-ER4
The Arista QSFP-40G-ER4 is a hot-swappable QSFP+ 40GBASE-ER4 optical transceiver for 40 Gbps Ethernet over duplex single-mode (G.652), with a Duplex LC interface and reach of up to 40 km SMF. Typical uses: 40G spine and aggregation links, 4 × 10G breakout and data-centre interconnect.
- 40 Gbps 40GBASE-ER4 up to 40 km SMF
- 40G over 40 km of single-mode
- Attenuate short links to protect the receiver
- Duplex LC connector · Duplex single-mode (G.652)
- Genuine Arista optic · GST invoice · pan-India dispatch
QSFP-40G-ER4: frequently asked questions
What is the Arista QSFP-40G-ER4?
The Arista QSFP-40G-ER4 is a QSFP+ 40GBASE-ER4 module from Arista Networks for 40 Gbps links. It plugs into a QSFP+ port on an Arista switch and is used for 40G spine and aggregation links, 4 × 10G breakout and data-centre interconnect.
What is the maximum distance of the QSFP-40G-ER4?
Arista specifies the QSFP-40G-ER4 for 40 km on duplex single-mode fiber (engineered link beyond 30 km). Arista notes that proper optical attenuation is required on shorter links to protect the receiver from damage.
What are the transmit and receive power levels of the QSFP-40G-ER4?
Per Arista's published optics data sheet, the QSFP-40G-ER4 transmits −2.7 to +3.8 dBm/lane and receives −21.2 to −4.5 dBm/lane.
Which fiber and connector does the QSFP-40G-ER4 need?
The QSFP-40G-ER4 uses a Duplex LC connector on duplex single-mode (G.652), at 4 lambda WDM, 1310 nm band. Both ends of the link must use the same optical standard.
Is the QSFP-40G-ER4 compatible with my Arista switch?
It works in Arista switches with QSFP+ ports that support this optic. Send us your switch model and EOS version and we will check it against Arista's Transceiver and Cable Guide before dispatch, so you only receive a module that works in your port.
QSFP-40G-ER4 vs QSFP-40G-LR4: which reach do I need?
QSFP-40G-LR4 covers 10 km; QSFP-40G-ER4 covers 40 km. ER4 needs optical attenuation on shorter links.
Is your QSFP-40G-ER4 genuine Arista?
Yes. Next Gen Networks supplies original Arista Networks optics, not third-party lookalikes or grey-market stock. Every unit is checked before dispatch, and we share the serial numbers on request so you can verify them in EOS ('show inventory').
What is the QSFP-40G-ER4 price in India and how do I order?
The Arista QSFP-40G-ER4 price in India depends on quantity, delivery city and current stock. Next Gen Networks supplies it with a GST invoice (input tax credit ready) and pan-India dispatch from New Delhi. Send the part number, quantity and delivery city on WhatsApp +91-7827955775 or email Sales@nextgennetworks.in and we reply with a GST quote.
How much power does the QSFP-40G-ER4 draw?
Arista lists maximum power of 3.5 W for the QSFP-40G-ER4. Check your switch's per-port power budget for dense deployments.
Documents
NextGen datasheetPDF · specs, FAQ & buying guideManufacturer datasheet
Arista family datasheet
Related Arista parts
QSFP-40G-LR440GBASE-LR4, 10 km SMFQSFP-40G-SR440GBASE-SR4, 100 m OM3 / 150 m OM4QSFP-40G-XSR440GBASE-XSR4, 300 m OM3 / 400 m OM4QSFP-40G-SRBD40GBASE-BIDI, 100 m OM3 / 150 m OM4QSFP-40G-SRBD-R40GBASE-BIDI, 100 m OM3 / 150 m OM4QSFP-40G-UNIV40GBASE-UNIV, 150 m MMF / 500 m SMFGovernment, PSU and enterprise orders welcome. GST invoice and pan-India delivery.
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