QSFP-40G-ER4: Cisco 40GBASE-ER4 QSFP+ Transceiver (40G, CWDM ~1310nm, 40km, LC, SMF)
MPN: QSFP-40G-ER4|By: Cisco

Starting from
$7,405
Indicative. Final pricing is confirmed with your quote.
In Stockships worldwide
- Condition:
- New (authorized channel)
- Warranty:
- Full manufacturer warranty
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Bulk order? Request volume pricing
Authorized & warrantied
Sourced through authorized distribution, with the full manufacturer warranty.
Compatibility checked
Validated against your server platform before dispatch.
Delivery & lead time
Confirmed with your quote, including expedited freight where available.
Business & public sector
POs, net terms and volume pricing for qualified organizations, government and edu.
Product overview
This is the Cisco 40GBASE-ER4 QSFP+ Transceiver (40G, CWDM ~1310nm, 40km, LC, SMF), order code QSFP-40G-ER4. Reach, fibre type and connector have to agree along the whole path, and a patch panel in the middle counts. Send the run length and the fibre already installed and we will match it.
We return an itemised quote within 48 business hours, and we say plainly when a part is constrained rather than quoting a date we cannot hold.
Specifications
General
- Manufacturer part number
- QSFP-40G-ER4
- Product Type
- Transceivers & Cables
- Manufacturer
- Cisco
Technical specifications
- Transceiver Type
- CWDM
Interfaces & connectivity
- Connector
- LC
- Optical Standard
- 40GBASE-ER4
These are the 5 facts we can state about QSFP-40G-ER4 without inferring anything. Compatibility beyond this is confirmed per platform, on request, before you order.
Where the Cisco QSFP-40G-ER4 is deployed
- Like-for-like replacement of QSFP-40G-ER4 in an existing system
- Replacing an optic that has started erroring
- Cabling a new rack into an installed fabric
Who this part is for
- MSPs holding spare optics against a customer SLA
- Integrators supplying the passive layer with a switch order
- Network teams matching optics at both ends of an existing link
What you get ordering this from us
Ordered by part number
Quoted and supplied against QSFP-40G-ER4 specifically, so what arrives is what your build sheet asks for.
Answered by a human
A quote comes back with the reasoning attached, including the cases where we think you should buy something else.
Volume pricing
The listed price is per unit; tiered pricing applies at quantity and purchase orders are accepted.
Questions buyers ask about this part
Is QSFP-40G-ER4 genuine and is the warranty intact?
Yes. It ships new in Cisco packaging, which is what keeps the warranty and the firmware entitlement valid. Anything we cannot supply that way we tell you about before you order.
Will QSFP-40G-ER4 work in my server?
Tell us the switch at both ends of the link. Optics are frequently vendor-coded, so a module that is electrically correct can still refuse to come up; we confirm the coding for both ends before it ships.
Do you accept purchase orders and quote at volume?
Yes, POs from qualified organisations, net terms on approval, and banded pricing once the quantity is worth banding. Send the number and we will price it properly.
Compare other Transceivers & Cables we stock
| Model | Brand | Key spec | Availability | From |
|---|---|---|---|---|
| 10G SFP+ SR 850nm 300m Optical Transceiver Module | NVIDIA Networking | Speed: 10Gb/s | In Stock | $40 |
| Arista 1G SFP SX 850nm Optical Transceiver Module | Arista | Speed: 1Gb/s | In Stock | $50 |
| Juniper 1G SFP SX 850nm Optical Transceiver Module | Juniper | Speed: 1Gb/s | In Stock | $50 |
| HPE 1G SFP SX 850nm Optical Transceiver Module | HPE | Speed: 1Gb/s | In Stock | $50 |
| Dell Technologies 1G SFP SX 850nm Optical Transceiver Module | Dell Technologies | Speed: 1Gb/s | In Stock | $50 |
| Intel 1G SFP SX 850nm Optical Transceiver Module | Intel | Speed: 1Gb/s | In Stock | $45 |
Browse all Transceivers & Cables or everything we stock from Cisco.
Specifying a system, not just the part?
Optics and cabling are part of the fabric spec on a cluster build, since both ends and the switch have to agree.
