# BlueOptics passive 400GBASE-CR8 QSFP-DD to 2×200GBASE-CR4 QSFP56 DAC breakout cable, 1 m, AWG26 (R8M51A-BL)

**URL:** https://aio.lv/en/product--blueoptics-r8m51a-bl--12266983
**Data updated:** 2026-04-14 22:37 (EEST)
**Category:** Network Cables
**Manufacturer:** BlueOptics
**Manufacturer code:** R8M51A-BL
**EAN:** 4063232351285
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 163.99 €
**Prices and availability valid until:** 2026-08-26 23:59
**Price without VAT (21%):** 135.53 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--blueoptics-r8m51a-bl--12266983

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 25.08.2026 | free |
| Pickup points | 28.08.2026 | 1.79 EUR |
| Courier delivery to door | 28.08.2026 | 4.99 EUR |

## Summary description

Passive Direct Attach Breakout cable by BlueOptics (MPN R8M51A-BL) converting a 400GBASE-CR8 QSFP-DD port to two 200GBASE-CR4 QSFP56 links. Single‑meter, AWG26 construction for short‑reach copper connections in data centers and network aggregation. Ideal for high‑density switches, server uplinks and equipment interconnects requiring 400G-to-2×200G breakout functionality.

## Long description

The BlueOptics passive 400GBASE-CR8 QSFP-DD to 2×200GBASE-CR4 QSFP56 DAC breakout cable, 1 m, AWG26 is a short-reach copper direct attach cable designed to split a single 400G QSFP-DD interface into two independent 200G QSFP56 links. Built for data centre and network aggregation environments, this 1-metre passive DAC provides a compact, low-latency connection option for high-density switches, server uplinks and equipment interconnects where 400G-to-2×200G breakout functionality is required.
Advantages
The passive construction and AWG26 conductor provide reliable signal integrity for short-reach connections while avoiding the need for transceivers in each port. The QSFP-DD to QSFP56 breakout format supports conversion of a single 400G port into two 200G links without active components, reducing power consumption and simplifying cabling. At one metre length the cable is suitable for top-of-rack and adjacent-rack connections, offering a compact, cost-effective option for dense network deployments.
Suitable for
 High-density switch-to-switch links in data centres
 Server uplinks requiring breakout from 400G to two 200G ports
 Network aggregation and spine-leaf topologies with QSFP-DD and QSFP56 ports
 Short-reach copper connections in rack and cabinet environments
When it may not be suitable
This passive DAC is intended for short-reach connections and is not suitable for long-distance links or runs that exceed the specified one-metre length. Because it is a passive direct attach cable, it does not include active signal conditioning or optical transceivers and therefore is not appropriate where optical fibre connections or active retiming are required.
Key specifications
 Cable type: Passive direct attach copper breakout cable
 Interface: QSFP-DD (400GBASE-CR8) to 2 × QSFP56 (200GBASE-CR4)
 Length: 1 metre
 Conductor size: AWG26
 Application: Short-reach data centre and rack interconnects
 Latency: Low (passive copper link)
How to use
Insert the QSFP-DD end into the 400G-capable port on the source switch or device and insert each QSFP56 end into the corresponding 200G ports on the target devices. Ensure both ends are fully seated and latched according to the equipment manufacturer’s guidance. Verify link status on connected devices and configure network interfaces as required for 200G operation. Handle the cable by the connector housings to avoid stress on the contacts and keep the cable within the recommended bend radius during installation.
What to consider before purchase
 Confirm that both source and target equipment support the QSFP-DD and QSFP56 interfaces and the required 400G-to-2×200G breakout mode.
 Verify that a 1-metre passive copper link meets your distance and environmental requirements.
 Check switch firmware and vendor compatibility lists for supported direct attach breakout cables.
Usage recommendations
Use this AWG26 passive DAC for short, high-density connections within racks or between adjacent racks where low latency and minimal power draw are priorities. Keep the cable tidy within cable management channels and avoid tight bends to maintain signal performance.

## FAQ

### How much does the BlueOptics 400GBASE-CR8 to 2×200GBASE-CR4 DAC R8M51A-BL cost, and is it available for purchase?

The price is 163.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 6 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 25.08.2026 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 BlueOptics 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 BlueOptics 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