# Optical QSFP Transceiver BlueOptics BO25K859S3D 40GBASE-ESR4 Multimode Fiber

**URL:** https://aio.lv/en/product--blueoptics-jh681a-bo--11353738
**Data updated:** 2026-03-07 19:59 (EET)
**Category:** Network Transceiver Modules
**Manufacturer:** BlueOptics
**Manufacturer code:** JH681A-BO
**EAN:** 4063232245133
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 119.49 €
**Prices and availability valid until:** 2026-07-25 23:59
**Price without VAT (21%):** 98.75 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--blueoptics-jh681a-bo--11353738

## 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

BlueOptics BO25K859S3D is a QSFP optical transceiver supporting 40GBASE-ESR4 over multimode fiber. Designed for high-speed data links and aggregation in datacenter and enterprise networks, it provides a compact QSFP form factor for 40 Gbit/s connectivity. Suitable for short-reach multimode applications, it enables reliable high-bandwidth connections and easy hot-plug installation.

## Long description

BlueOptics BO25K859S3D is a QSFP optical transceiver module engineered for 40GBASE-ESR4 multimode fiber links. It occupies a compact QSFP form factor and supports four parallel lanes to deliver aggregate 40 Gbit/s throughput for short-reach multimode applications. The module is intended for use in data center and enterprise aggregation, switch-to-switch uplinks, and high-density fiber patch deployments where reliable, hot-pluggable 40 Gb/s connectivity is required.
Advantages
The transceiver offers a compact QSFP design that enables high port density in switches and routers, while supporting multimode fiber to keep link costs and cabling complexity lower for short distances. Hot-pluggable operation simplifies installation and replacement without powering down equipment. Designed for 40GBASE-ESR4 operation, it provides stable aggregate throughput across the four parallel lanes and is compatible with common multimode fiber cabling practices used in datacenter environments.
Suitable for
Data center switch-to-switch uplinks and aggregation
High-density server or switch port expansion
Short-reach multimode fiber links within campus or enterprise networks
Fiber patch panels and optical distribution in rack deployments
Key specifications
Form factor: QSFP (Quad Small Form-factor Pluggable)
Data rate: 40 Gbit/s aggregate (four lanes)
Standard: 40GBASE-ESR4 for multimode fiber
Fiber type: Multimode fiber (OM3/OM4 compatible for short reaches)
Distance: short-reach multimode links (designed for intra-data-center distances)
Connector: MPO/MTP-style parallel fiber interface
Hot-pluggable: yes
How to use
Insert the QSFP transceiver into a compatible QSFP port on a switch or router until it seats firmly; avoid excessive force. Connect an MPO/MTP parallel multimode fiber cable between the transceiver and the remote device or patch panel, ensuring correct fiber polarity and that the fiber type (OM3/OM4) matches the intended distance. After physical installation, verify link status in the host device management interface and ensure the port speed and lane configuration are set for 40GBASE-ESR4 operation. Handle the module by its edges and keep dust caps on fiber connectors when not in use to prevent contamination.
Usage recommendations
Use this QSFP transceiver with high-quality OM3 or OM4 multimode fiber and MPO/MTP trunk cables for reliable short-reach 40G links. Ensure proper cable polarity and cleanliness during installation, and confirm compatibility with the host equipment's QSFP interface and firmware to avoid interoperability issues.

## FAQ

### How much does the QSFP Transceiver BlueOptics BO25K859S3D 40GBASE-ESR4 cost, and is it available for purchase?

The price is 119.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 86 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 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

## Image

https://aio.lv/img/cache/product/11353738/65820837_large.webp