Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Enjoy free shipping during the holidays! Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.

Enjoy Our Extended FREE RETURNS

We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later). We'll even cover the cost of return shipping. Learn more about our Return Policy.

Shopping Cart
Questions & Answers
is there a way to turn of the shake awake feature? Expert Answer

Yes, if you refer to your instruction manual it will provide a way to turn the "Shake Awake" feature off. This is the generic instructions provided by Holosun:

The default sleep timer setting is 10 min, but can be adjusted
1) Press and hold the “+” button for 10 seconds to enter time adjustment mode. There are 4 options: 10 min, 1h, 12h or the sleep mode is disabled.
2) Press and release either “+” or “-” button to set the time. The LED will blink (1=10 min,2=1h, 3=12h, or4=disable sleep mode.
3) Press the “+” and “-” buttons simultaneously to save the time setting and power off the sight

by Armando R., Gear Expert, March 11, 2020
The description says “parallax-free”,but the red dot I received is definitely NOT parallax-free.The red “dot” is also more like a smudge. This Normal? Expert Answer

If the red dot looks like a smudge, you might have what is called a stigmatism which blurs those types of dots, I have a stigmatism and experience the same thing.

by Ben, Gear Expert, January 22, 2021
Customer Reviews
Helpful Positive Review
Holosun Red Dot by Matteo, Verified Owner, October 13, 2024
Not a bad sight. Mainly wanted it because it came in FDE to match l a build I was working. Could probably find a similar quality red dot for less, but overall does the job. Note that it is a lower 1/3 sight, so will not absolute co-witness.
1/2 found this helpful
Helpful Positive Review
Holosun easy to set up, and very easy to use. by Ziggy, Verified Owner, April 11, 2024
I like this Holosun Paralow HS403B 1x20mm 2 MOA Red Dot Sight very much. It was reasonable priced and easy to use and sight in. I have this on my bedroom anti-home invasion weapon. I did recommend this and my buddy bought two.
1/1 found this helpful
Helpful Positive Review
Great Red Dot by A.Feaze, Verified Owner, May 25, 2024
Holosun 403B is a great red dot and works well. Worth it especially on sale!
1/1 found this helpful
Helpful Positive Review
Great red dot by XtwebbyX, September 5, 2024
Great red dot. Dot has multiple brightness settings, which is nice.
1/1 found this helpful
Helpful Positive Review
Best bang for your buck by Joe, Verified Owner, November 11, 2024
This optic has what you need for most situations, it is at a great price for what you get and it is easy to use and install.
1/1 found this helpful
Helpful Positive Review
Very pleases as always with Holosun products. by Miket.435, Verified Owner, January 19, 2025
I own 5 Holosun red dots and a 3X magnifier and have been very pleased with all at a great price. I bought the HS403B in FDE for my Ruger takedown in the FDE Magpul Backpacker stock equipped with the TacSol fluted barrel in Quicksand color. The FDE o...
Read More...
1/1 found this helpful
Read All 213 Reviews
Color: Flat Dark Earth Finish: Micro Arc Fabric/Material: CNC Aluminum Magnification: 1 xObjective Lens Diameter: 20 mmReticle: 2 MOA Dot Illumination Type: LED Illumination Color: Red Eye Relief: Unlimited Adjustment Click Value: 0.5 in at 100 ydsEmitter Type: Enclosed Lens Material: Glass Optical Coating: Multi-Layer Reflecting Battery Type: CR2032 Battery Life: Up to 5 years Operating Temperature: 22 - 140 FahrenheitWater Resistance Level: Waterproof Water Resistant Mark: 1 mLength: 63 mmWidth: 30 mmHeight: 58 mmWeight: 124 gIncluded Accessories: 1/3 Co-witness Mount , Low Mount Condition: New Package Type: Box Magnification Type: Fixed Brightness Index: 2NV / 10DL Quantity: 1 Tube Diameter: 22 mmRed Dot Sights-Footprint: Not Applicable Adjustment Range: 0.5 MOAAttachment Type: Low Profile , Quick Detach Co-Witness: 1/3 Co-Witness Housing/Frame Material: 6061-T6 aluminum W/E Travel at 100 Yds: 50 MOA

Code: 28Y-RD-PRLWRDS-HS403B-FDE

MPN: HS403B FDE

UPC: 605930624762

Product No Longer Available

Product Info for Holosun Paralow HS403B 1x20mm 2 MOA Red Dot Sight

The Holosun Paralow Lightweight Red Dot Sight is packed full of features and design qualities that make this a versatile must-have for any shooter, whether you're on the range or in the field. These Red Dot Sights by Holosun allow you to have greater situational awareness with the ability to shoot with both eyes open using the parallax-free 2 MOA dot to acquire your target. It breaks the mold with an innovative 50,000 hour battery life and an auto wake feature that turns the scope on when it's moved and has an adjustable auto shut-off. The high-grade aluminum construction and weather-resistant finish is waterproof down to 1m, so you can take your Holosun Paralow Waterproof Red Dot Sight everywhere you go in any extreme weather condition. Reduce your training time and increase your accuracy with the Holosun Paralow Compact Red Dot Sight.image

Features of Holosun Paralow HS403B 1x20 mm 2 MOA Red Dot Sight:

  • Designed for day and night use
  • Advanced LED technology allows for up to 50,000 of operation
  • 2 MOA dot size
  • Parallax-free with unlimited eye relief
  • Unaffected by extreme weather conditions
  • Rugged and reliable aluminum construction
  • All lenses have multi-layer coatings
  • Improved motion-activated "Shake Awake Technology"
  • Multiple brightness settings
  • Durable PEO/MAO finish

Package Contents:

  • Holosun Paralow Red Dot Sight, 2 MOA Dot, Parallax-Free
  • Lower 1/3 Co-witness Mount
  • Low Profile Mount
  • T10 L Key
  • Rubber Cover
  • User Manual
  • CR2032 Battery
  • Lens Cloth

Red Dot Accessories

160 / 60
Previous
Next

Red Dot Sight Magnifier

120 / 20
Previous
Next

Red Dot Sight Mounts

116 / 16
Previous
Next

Related Products to Holosun Paralow HS403B 1x20mm 2 MOA Red Dot Sight

Holosun Paralow HS403B 1x20mm 2 MOA Red Dot Sight Unavailable & Discontinued Models

List of Unorderable Models

  • Holosun Red Dot Sight 1x20mm, 2 MOA Dot, Flat Dark Earth, HS403B-FDE , MPN: HS403B FDE , UPC: 605930624762 , Code: 28Y-RD-PRLWRDS-HS403B-FDE
  • Holosun Paralow Red Dot Sight, 2 MOA Dot, Parallax-Free, Under Mount Battery, HS403A , MPN: HS403A , UPC: 760921087305 , Code: 28Y-RD-PRLWRDS-HS403A
  • Holosun Paralow Red Dot Sight 1x20mm, 2 MOA Dot, Parallax-Free, Battery Tray, HS403B , MPN: HS403B , UPC: 760921087428 , Code: 28Y-RD-PRLWRDS-HS403B
  • Holosun LED Red Dot Sight w/Kinetic Development SIDELOK Aimpoint Micro Mount Lower 1/3 Co-Witness, Flat Dark Earth , MPN: HS403B-FDE-KIT1 , Code: 28Y-RD-PRLWRDS-HS403B-FDE-KIT1
  • Holosun LED Red Dot Sight w/Low and Co-witness Mounts W/ Kinetic Development SIDELOK Aimpoint Micro Mount Lower 1/3 Co-Witness, Black , MPN: HS403B-KIT1 , Code: 28Y-RD-PRLWRDS-HS403B-KIT1
Compare (0)