QSFP-40G-LR4= — Cisco 40GBASE-LR4 QSFP+ Transceiver (40G, CWDM ~1310nm, 10km, LC, SMF)
MPN: QSFP-40G-LR4=|By: Cisco

Starting from
$1,065
Indicative — final pricing confirmed with your quote.
In Stockships worldwide
- Condition:
- New — authorized channel
- Warranty:
- Full manufacturer warranty
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Product overview
Cisco lists QSFP-40G-LR4= as a 40GBASE-LR4 QSFP+ Transceiver (40G, CWDM ~1310nm, 10km, LC, SMF). Direct-attach copper is cheaper and lower latency than optics but is limited by length and by what each switch will accept. Tell us the two endpoints and we will say which of the two is right for the run.
If the part is wrong for your platform we will say so and suggest the one that is, which is cheaper for both of us than a return.
Featuring
- Optical Standard
- 40GBASE-LR4
- Manufacturer
- Cisco
Interfaces / Ports
- Connector
- LC
Physical characteristics
- Transceiver Type
- LR4
- Product Type
- Transceivers & Cables
- Expedited shipping options are available — rates confirmed with your quote.
- Purchase orders accepted from qualified institutions.
- Compatibility is validated against your server platform before dispatch. Send us the model and we will confirm support.
The table below is what the transceiver is documented as, not what we have inferred from the part number. If the figure you need is missing, ask and we will source it from the manufacturer.
Where the Cisco QSFP-40G-LR4= is deployed
- Like-for-like replacement of QSFP-40G-LR4= in an existing system
- Replacing an optic that has started erroring
- Holding spare optics against a link-level SLA
Who this part is for
- MSPs holding spare optics against a customer SLA
- Integrators supplying the passive layer with a switch order
- Procurement buying optics in quantity for a scheduled build
What you get ordering this from us
Ordered by part number
Quoted and supplied against QSFP-40G-LR4= specifically, so what arrives is what your build sheet asks for.
Compatibility checked
We confirm the part is supported on your platform before it ships, rather than leaving the check to you.
Answered by a human
A quote comes back with the reasoning attached, including the cases where we think you should buy something else.
Questions buyers ask about this part
- Is QSFP-40G-LR4= 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-LR4= 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. Purchase orders are accepted from qualified organisations, net terms are available on approval, and tiered pricing applies at quantity. Tell us how many you need.
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Specifying a system, not just the part?
Optics and cabling are part of the fabric spec on a cluster build — both ends and the switch have to agree.
