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Monstrum

Monstrum Guardian 3-9x Rifle Scope with Illuminated MOA Reticle

Based on 172 reviews
Condition: New
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$59.99
Holiday Deal · 65% off was $169.99

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Availability: In Stock.
Fulfilled by Amazon
Arrives Friday, Nov 13
Order within 15 hours and 44 minutes

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At a glance

Condition
New
Style
Black | 3-9x40
Model
SG3940-B
Weight
15 oz
Color
Black
Material
Aluminum
Sport
Hunting
Works with
Rifle

Features 5

  • Adjustable 3-9 times magnification, for targeting out to 600 yards and beyond
  • Fully illuminated MOA reticle with MOA hashmarks for ranging information and inline dial controlled brightness adjustments
  • Aircraft grade 6061 aluminum scope body with a sealed, nitrogen-charged tube for resistance to water and fog
  • Precision 1/4 MOA/click windage and elevation adjustments

Description

The Monstrum Guardian Series is the latest iteration from our best selling line of SFP rifle scopes! The scope comes equipped with: Adjustable 3-9 times magnification, for targeting out to 600 yards and beyond Fully illuminated MOA reticle with MOA hashmarks for ranging information and inline dial controlled brightness adjustments Precision 1/4 MOA/click windage and elevation adjustments Anodized aircraft grade 6061 aluminum construction, for lightweight and durable performance An integrated throw lever for smooth and controlled adjustment of the magnification dial A sealed, nitrogen charged scope tube for resistance to fog and water The Guardian 3-9x weighs 15 ounces. It has a 1 inch diameter tube and requires a mount with 1 inch diameter scope rings. The scope is 12 inches in total length. Package includes: A set of medium profile scope rings compatible with all Picatinny or Weaver mounting platforms. A set of flip up lens covers One CR2032 battery

Specs 25

Brand Monstrum
Color Black
Style Black | 3-9x40
Product Dimensions 12"L x 1"W x 12"H
Sport Hunting
Item Weight 15 ounces
Material Aluminum
Magnification Maximum 9 x

Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Friday, Nov 13

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

Good bang for the buck
Style: Black | 3-9x40
Monstrum is frequently criticized on various forums for its low cost, leading many to advise against purchasing it. However, I believe many of these individuals have never actually used the scope. I had a Ruger 10/22 from the early 90's which had a Tasco 4x20 on it and it had yellowed throughout the years; I could hardly see through it. Since the gun was a 22 I decided to give Monstrum a try. I picked up the scope and rings for 49.99 plus tax. I am impressed that it is a 3-9x40 scope and the reticle lights up green or red. This also has .25 MOA adjustments. I mounted this on the gun and had no problem zeroing the gun. It was dead on at 25 yards. Also the optic was decently sharp. Monstrum does offer a life time warranty and I signed up for this through their website. I think this is a decent scope for a 22 or any other budget rifle. I would not recommend this scope for a mid range or higher end rifle build. For instance an equivalent Vortex entry level scope will cost about 150 and rings will be around 50 so you would pay 200 dollars. ... show more
Reviewed in the United States on July 4, 2025 by Kevin
A Real Bargain
Style: Black | 3-9x40
Excellent quality and performance at a very fair price. Works great on my 7.62x39 AR15.
Reviewed in the United States on June 5, 2025 by Superkicker
Decent enough for pcp airguns or rimfire rifles
Style: Black | 3-9x40
For the price, the scope performs as it needs to. The magnification at 9x doesn't really seem like it zooms in that much, the clarity is decent, but again, it's a budget scope. It has worked just fine on my PCP air rifle, sighted in without an issue, but not sure if it would hold up to a spring or gas ram style of airgun. The reticle is decent, but it could have been better defined on the "mil dot" aspect of it. Hard to use them properly because they're not crisp, clear dots as in some more expensive scopes. The scope is not a bad deal, but keep your expectations realistic when buying a budget scope 🤷 ... show more
Reviewed in the United States on February 21, 2023 by Joe
Good scope
Style: Black | 3-9x40
For the price it’s not bad I love that it have the resettable Tourette’s but kind feel the magnification kinda week set it up on a 10/22 lvt it’s my sub sonic semi auto set up so I don’t shoot it much past 50 yards it’s a hunting set up but with the resettable Tourette’s I can adjust it out to 100 yards in with the flip up scope caps I’ve got the settings for 75 and 100 written in the camp I’m a big fan of the monstrum scope I run several of there ffp on my match rifles n they are always in the top 3 I even with guys running nightforce and other high end scopes ... show more
Reviewed in the United States on May 25, 2025 by adam
Worth the money
Style: Black | 3-9x40
Better than some much more expensive.
Reviewed in the United States on July 21, 2025 by Robert K. Kilpatrick
Inexpensive scope.
Style: Black | 3-9x40
Was about what I thought for a inexpensive scope it sighed in fairly quick, not as clear as I would like, the cross hairs are not well defined. Now to see it it will last on my 300 BLK. I do like the choice of red or green illumination.
Reviewed in the United States on November 28, 2025 by PRZ
10/10
Style: Black | 3-9x40
Incredible, eye relief is great, clarity is great, every thing is great!
Reviewed in the United States on September 10, 2025 by Nick D
Great Scope
Style: Black | 3-9x40
Excellent scope the lens is clear as any scope that cost 4x
Reviewed in the United States on July 21, 2025 by Jimmy Carter
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