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- USA
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Ships within 48 hours · Estimated delivery Jul 15 - Jul 20
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Description
Sera Marin HydrometerFor easy monitoring of marine water density, you can determine the salinity (salt content) from the measured density. It's essential to maintain a consistent salinity level in your aquarium, so it's important to check the water regularly. To perform the test, fill a tall glass with the water you want to assess, then read the scale of the submerged hydrometer based on how deep it is immersed.
For easy monitoring of marine water density, you can determine the salinity (salt content) from the measured density. It's essential to maintain a consistent salinity level in your aquarium, so it's important to check the water regularly. To perform the test, fill a tall glass with the water you want to assess, then read the scale of the submerged hydrometer based on how deep it is immersed.Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.1 ★★★★★
Based on 2323 reviews
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Product Reviews
★★★★★ 4
Terrific addition to your backpacking gear
I like this map holder for its versatility in holding different size maps. Once sealed, it was very effective at keeping moisture out and protecting the maps. I originally used this on a 13K mountain ascent. Worked great. The only thing that can be tricky at times is sealing the top. It's not as easy as sealing a typical zip-loc kitchen bag, takes some doing to get it to seal.
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Reviewed in the United States on May 26, 2025
★★★★★ 5
Best Map Case Ever!!!
Size: Regular - 12 x 16 Inches
Best Map case in the market! Field tested and keeps everything dry. The size is fantastic and you can run paracord through the rings. I would recommend this to anyone that uses a map. You definitely pay for what you get and that's high quality and functionality.
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Reviewed in the United States on August 13, 2025
★★★★★ 5
Just right for protecting river trip guides
Size: Regular - 12 x 16 Inches
Nice and durable - heavy duty. Getting ziplock to close is a pain though - lick or spit helps.
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Reviewed in the United States on December 19, 2024
★★★★★ 5
It works
Size: Large - 16 x 22 Inches
It works great nothing bad to say about it
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Reviewed in the United States on February 6, 2026
★★★★★ 5
Great map case
Size: Regular - 12 x 16 Inches
Love this map case, it hard at times to close the zip lock!
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Reviewed in the United States on June 6, 2025