---
product_id: 270153121
title: "NF-A4x20 FLX, Premium Quiet Fan, 3-Pin (40x20mm, Brown)"
brand: "noctua"
price: "₨20241"
currency: LKR
in_stock: true
reviews_count: 3
url: https://www.desertcart.lk/products/270153121-nf-a4x20-flx-premium-quiet-fan-3-pin-40x20mm-brown
store_origin: LK
region: Sri Lanka
---

# 3-speed 3700-5000 RPM FLX control 40x40x20mm compact size Ultra-quiet max 14.9 dB(A) NF-A4x20 FLX, Premium Quiet Fan, 3-Pin (40x20mm, Brown)

**Brand:** noctua
**Price:** ₨20241
**Availability:** ✅ In Stock

## Summary

> 🌀 Elevate your gear’s cool factor—silence and power in perfect harmony!

## Quick Answers

- **What is this?** NF-A4x20 FLX, Premium Quiet Fan, 3-Pin (40x20mm, Brown) by noctua
- **How much does it cost?** ₨20241 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.lk](https://www.desertcart.lk/products/270153121-nf-a4x20-flx-premium-quiet-fan-3-pin-40x20mm-brown)

## Best For

- noctua enthusiasts

## Why This Product

- Trusted noctua brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Compact Powerhouse:** Ultra-slim 40x40x20mm design fits perfectly in tight 1U spaces, ideal for network gear, NAS, and DVRs.
- • **Whisper-Quiet Cooling:** Experience near-silent airflow with industry-leading 14.9 dB(A) noise levels—because your workspace deserves peace.
- • **Plug & Play Versatility:** Includes OmniJoin™ adaptor set and 3-pin Molex connector for seamless integration with proprietary fan headers.
- • **Award-Winning Aerodynamics:** Flow Acceleration Channels and Advanced Acoustic Optimisation frame deliver superior airflow with minimal noise.
- • **Precision 3-Speed Flexibility:** Tailor your cooling with three RPM settings (3700/4400/5000) for optimal performance and energy efficiency.

## Overview

The Noctua NF-A4x20 FLX is a premium 40x40x20mm quiet fan engineered for professional-grade cooling in compact spaces. Featuring advanced aerodynamic design, ultra-low noise levels (max 14.9 dB(A)), and flexible 3-speed control, it’s the go-to upgrade for network equipment, NAS, and other sensitive devices demanding silent, reliable airflow.

## Description

Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctua’s AAO frame, the NF-A4x20 is a highly optimised, premium-quality quiet fan in size 40x20mm. The FLX version provides 5000/4400/3700rpm speed settings via the supplied Low-Noise Adaptors and includes the OmniJoin™ Adaptor Set for easy connection to proprietary fan headers. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands.

Review: Amazing silent fan - I order two silent fans and replace a very loud original fans for network switch. Amazing performance no sound at all.
Review: Excellent product - This items working perfectly more than original FANs which coming on QNAP 10g managed switch. Very quiet and cooling the switch. Highly Recommended for others

## Features

- Premium quiet fan, 40x40x20 mm, 12V, 3-pin Molex, 5000/4400/370 RPM, max. 14.9 dB(A), >150,000 h MTTF
- Award-winning A-series design with Flow Acceleration Channels and Advanced Acoustic Optimisation frame for superior quiet cooling performance
- 40x20mm size ideal for 1U applications or replacing fans in network and storage equipment (routers, switches, NAS etc.) or other devices such as DVRs

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B071J8CZP9 |
| Best Sellers Rank | #16,904 in Computers ( See Top 100 in Computers ) #88 in Computer Case Fans |
| Brand | Noctua |
| Brand Name | Noctua |
| Compatible Devices | Desktop, Laptop |
| Compatible devices | Desktop, Laptop |
| Cooling Method | Air |
| Cooling method | Air |
| Customer Reviews | 4.8 out of 5 stars 4,744 Reviews |
| Global Trade Identification Number | 09010018100112 |
| Item Dimensions L x W x H | 20L x 40W x 40H millimeters |
| Item Weight | 50 Grams |
| Manufacturer | Noctua |
| Material Type | Fibre-glass reinforced PBT |
| Maximum Rotational Speed | 3500 RPM |
| Noise Level | 14.9 Decibels |
| Power Connector Type | 3-Pin |
| Power connector type | 3-Pin |
| Product dimensions | 20L x 40W x 40H millimeters |
| Unit Count | 1.0 Count |
| Voltage | 12 Volts |

## Product Details

- **Brand:** Noctua
- **Cooling method:** Air
- **Power connector type:** 3-Pin
- **Product dimensions:** 20L x 40W x 40H millimeters
- **Voltage:** 12 Volts

## Images

![NF-A4x20 FLX, Premium Quiet Fan, 3-Pin (40x20mm, Brown) - Image 1](https://m.media-amazon.com/images/I/71lyRpVR4OL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Amazing silent fan
*by R***X on 12 November 2022*

I order two silent fans and replace a very loud original fans for network switch. Amazing performance no sound at all.

### ⭐⭐⭐⭐⭐ Excellent product
*by M***I on 20 October 2022*

This items working perfectly more than original FANs which coming on QNAP 10g managed switch. Very quiet and cooling the switch. Highly Recommended for others

### ⭐⭐⭐⭐⭐ Very quiet
*by J***I on 23 April 2022*

Bought this to replace my noisy 3D printer hotend fan. It is quiet now.

## Frequently Bought Together

- Noctua NF-A4x20 FLX, Premium Quiet Fan, 3-Pin (40x20mm, Brown)
- Noctua NF-A4x10 FLX, Premium Quiet Fan, 3-Pin (40x10mm, Brown)

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**Shop now:** [https://www.desertcart.lk/products/270153121-nf-a4x20-flx-premium-quiet-fan-3-pin-40x20mm-brown](https://www.desertcart.lk/products/270153121-nf-a4x20-flx-premium-quiet-fan-3-pin-40x20mm-brown)

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*Product available on Desertcart Sri Lanka*
*Store origin: LK*
*Last updated: 2026-02-03*