# Optical attenuator CBO SFA21BK4 Singlemode LC Simplex 4 dB

**URL:** https://aio.lv/en/product--blueoptics-sfa21bk4--4467306
**Data updated:** 2026-02-25 16:32 (EET)
**Category:** Fiber Optic Cables
**Manufacturer:** BlueOptics
**Manufacturer code:** SFA21BK4
**EAN:** 4063232044590
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 29.99 €
**Prices and availability valid until:** 2026-07-21 23:59
**Price without VAT (21%):** 24.79 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--blueoptics-sfa21bk4--4467306

## 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

Passive optical attenuator CBO SFA21BK4, designed for singlemode fiber networks with an LC simplex connector and 4 dB fixed attenuation. Provides controlled reduction of optical power to protect receivers and balance signal levels in fiber links. Suitable for testing, installations, and maintenance in telecommunications and data center environments.

## Long description

Optical attenuator CBO SFA21BK4 Singlemode LC Simplex 4 dB is a passive inline device designed for singlemode fibre networks. It features an LC simplex connector and a fixed 4 dB attenuation, providing precise reduction of optical power to protect sensitive receivers and to equalize signal levels across fibre links. The attenuator is suitable for installation in telecommunications, data centre patch panels and test setups where consistent optical loss is required.
Advantages
The attenuator offers a compact form factor with stable, repeatable attenuation and low insertion loss beyond the specified 4 dB reduction. Its LC simplex interface ensures compatibility with standard singlemode jumper cables and patch panels. As a passive component it requires no power and provides immediate attenuation without calibration, reducing risk of receiver saturation and facilitating signal balancing in multi-span links.
Suitable for
Protecting optical receivers from high input power
Balancing signal levels between transmitters and receivers in singlemode networks
Temporary insertion for commissioning and maintenance tasks
Use in test benches and measurement setups for controlled power reduction
Key specifications
Fiber type: singlemode (SM)
Connector type: LC simplex
Attenuation value: fixed 4 dB
Polarisation: non-polarising design suitable for standard singlemode operation
Operating wavelength range: compatible with typical singlemode telecom wavelengths (e.g. 1310 nm / 1550 nm)
Form factor: inline, compact attenuation module for patch panels and pigtail connections
How to use
Insert the LC simplex connector of the attenuator between the transmitting or receiving fibre jumper and the device requiring reduced optical power. Ensure connectors are clean before mating to prevent additional loss or contamination. The fixed 4 dB attenuation is applied immediately upon connection; no configuration or power supply is required. For rack or panel installations, route the fibre carefully to avoid sharp bends and secure the attenuator in the patching area to prevent strain on the connectors.
Usage recommendations
Prior to insertion, inspect and clean LC connectors with suitable fibre cleaning tools. Use the attenuator in environments within manufacturer-recommended temperature and humidity ranges and avoid exposure to direct mechanical stress. For systems where precise attenuation across a wide wavelength range is required, confirm optical budget margins and use a calibrated optical power meter to verify power levels after installation.

## FAQ

### How much does the Optical attenuator CBO SFA21BK4 LC 4 dB cost, and is it available for purchase?

The price is 29.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 70 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/4467306/59855565_large.webp