# StarTech QSFP+ 40GBASE-SR4 QSFP-40G-CSR4-ST 40GbE Multimode MPO 850nm 300–400m DDM

**URL:** https://aio.lv/en/product--startech-qsfp-40g-csr4-st--4260537
**Data updated:** 2026-01-13 21:20 (EET)
**Category:** Network Media Converters
**Manufacturer:** StarTech
**Manufacturer code:** QSFP-40G-CSR4-ST
**EAN:** 0065030886031
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 61.49 €
**Prices and availability valid until:** 2026-07-24 23:59
**Price without VAT (21%):** 50.82 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--startech-qsfp-40g-csr4-st--4260537

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 23.07.2026 | free |
| Pickup points | 28.07.2026 | 1.89 EUR |
| Courier delivery to door | 28.07.2026 | 4.99 EUR |

## Summary description

Compatible StarTech QSFP+ transceiver (model QSFP-40G-CSR4-ST) for 40GbE networks using multimode fiber. Supports 40GBASE-SR4 at 40,000 Mbit/s over MPO connector at 850 nm with digital diagnostic monitoring (DDM). Intended for short-range links up to 300–400 m depending on fiber type. Compact silver module, SFP+ interface, MTBF ~95,832,027 h, ideal for data center aggregation and high-speed switching.

## Long description

The StarTech QSFP+ 40GBASE-SR4 QSFP-40G-CSR4-ST is a compatible QSFP+ transceiver module designed for 40GbE multimode fiber links. It operates at 850 nm over an MPO connector and supports the 40GBASE-SR4 standard with a maximum data rate of 40,000 Mbit/s. The module offers digital diagnostic monitoring (DDM) for real-time monitoring of optical and electrical parameters and is intended for short-range connections with a maximum transfer distance of up to 300–400 m depending on the multimode fiber type. The compact silver enclosure is lightweight and suited for use in high-density data center aggregation and high-speed switching environments.
Advantages
This QSFP+ transceiver provides a high-speed 40GbE interface in a compact form factor while maintaining compatibility with standard multimode MPO cabling. Integrated digital diagnostic monitoring enables continuous insight into module status and link conditions. The module’s optical design supports short-range multimode links up to the stated distance range, enabling consolidation of high-bandwidth connections in aggregation and switching layers. Its silver, lightweight construction aids hot-swap handling and rack-level deployment in dense installations.
Suitable for
Data center aggregation switches and spine-leaf fabrics
High-density optic uplinks between switches and servers
Short-range multimode fiber connections within campus or enterprise buildings
40GbE link deployments requiring MPO connectivity and DDM
Key specifications
Maximum data transfer rate: 40,000 Mbit/s
Optical standard: 40GBASE-SR4 (multimode)
Wavelength: 850 nm
Connector type: MPO
Maximum transfer distance: up to 300–400 m (dependent on multimode fiber type)
Digital Diagnostic Monitoring (DDM): supported
Form factor: QSFP+ transceiver
Colour: Silver
Weight: 0.0375 kg
How to use
Install the QSFP-40G-CSR4-ST module into a compatible QSFP+ port on a network switch or optical appliance, ensuring the device is powered down or supports hot-swap insertion according to the host equipment instructions. Connect a compatible MPO multimode fiber cable to the module’s MPO connector, observing correct polarity and fiber type to achieve the stated distances. Monitor the module’s DDM output via the host device management interface to verify optical power, temperature, and other diagnostic parameters. Follow your switch or server documentation for link activation and port configuration to enable 40GBASE-SR4 operation.
Usage recommendations
Use certified multimode fiber (OM3/OM4 as applicable) and MPO cables to reach the expected link distances; verify fiber type and link loss before installation. Ensure the host equipment firmware and driver support third-party QSFP+ modules and confirm DDM visibility through management tools. Handle the module using ESD-safe practices and protect the MPO connector with dust caps when not connected.

## Specifications

| Feature | Value |
|---|---|
| Interface type | SFP+ |
| Compatible products | QSFP-40G-CSR4 |
| Number of products included | 1 pc(s) |
| Brand compatibility | Cisco |
| SFP transceiver type | Fiber optic |
| Multi-mode fiber (MMF) supported | Yes |
| SFP transceiver standard | SR4 |

### Network

| Feature | Value |
|---|---|
| Maximum data transfer rate | 40000 Mbit/s |
| Fiber ethernet cabling technology | 40GBASE |

### Ports & interfaces

| Feature | Value |
|---|---|
| Fiber optic connector | MPO |

### Performance

| Feature | Value |
|---|---|
| Maximum transfer distance | 400 m |
| Mean time between failures (MTBF) | 95832027 h |
| Wavelength | 850 nm |

### Weight & dimensions

| Feature | Value |
|---|---|
| Weight | 0.0375 kg |
| Height | 8.5 mm |
| Width | 122 mm |
| Depth | 18.6 mm |

### Logistics data

| Feature | Value |
|---|---|
| Master (outer) case height | 35 mm |
| Master (outer) case width | 120 mm |
| Master (outer) case length | 205 mm |
| Products per master (outer) case | 1 pc(s) |
| Harmonized System (HS) code | 85369010 |

### Features

| Feature | Value |
|---|---|
| Product colour | Silver |
| Hot-swap | Yes |
| Digital Diagnostics Monitoring (DDM) | Yes |

### Packaging data

| Feature | Value |
|---|---|
| Package weight | 60 g |
| Package depth | 205 mm |
| Package height | 35 mm |
| Package width | 120 mm |

### Sustainability

| Feature | Value |
|---|---|
| Sustainability certificates | RoHS, CE |

## FAQ

### How much does the StarTech QSFP+ 40GBASE-SR4 QSFP-40G-CSR4-ST cost, and is it available for purchase?

The price is 61.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 13 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 23.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All StarTech products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized StarTech service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

### How can I tell if this product suits my needs?

When making a choice, we recommend paying attention to the key features: maximum data transfer rate, maximum transfer distance, weight, fiber optic connector, product colour, compatibility with your devices or usage conditions, material quality, functionality, and warranty terms. These characteristics will help you determine how well the model meets your needs.

### Where can I download the instructions for StarTech QSFP+ 40GBASE-SR4 QSFP-40G-CSR4-ST?

You can download the instructions in PDF format from the “Instructions” section on the product description page. The file contains complete information about installation, setup, and usage.

## Image

https://aio.lv/img/cache/product/4260537/54605568_large.webp