GB2 Millbank Bag Water Prefilter

(3 customer reviews)


In stock



GB2 Millbank Bag

The GB2 Millbank Bag is the perfect, personal-sized prefilter/clarifier for your kit. This smaller version is sized to easily fold up and stow in your pocket, water bottle carrier, haversack, or pack.

Designed with the camper, hiker, backpacker, and bushcrafter in mind, the GB2 Millbank Bag is the perfect companion for your Grayl GeoPress or other water filter or purifier. Prefiltering, or clarifying your water prior to putting it through your filter will drastically increase the life of your filter or filter cartridge. 

The heavy duty canvas bag will remove most dirt, debris, particulates, and suspended organic material in the water that waterborne pathogens like to attach themselves to. This will improve taste and odor regardless of the method you choose to disinfect. 

This Millbank Bag Water Prefilter bag, like all cloth or canvas bags, does not achieve the necessary micron-level for disinfection by mechanical filtration, so it is important to note that this is a prefilter that clarifies water to improve taste, odor, and overall palatability. It also increases the life of and effectiveness of your filter. It DOES NOT make water safe to drink. You must still disinfect it in some way using a filter, purifier, chemical, or thermal means.


  • Heavy Cotton Canvas
  • Double Stitched
  • Heavy, Industrial Polyester Thread stands up to moisture and UV
  • Comes with a strong paracord lanyard for hanging
  • 48oz. Capacity
  • Measures 10.5 x 6.5 inches
  • Weighs 1.4oz
  • 1-yr Warranty on Material and Workmanship

GB2 Made in the USA

Proudly Made for GB2 in the Oklahoma by Millbank Bags USA

What are the benefits of using a Millbank Bag as a prefilter?

Prefiltering, or clarifying, will remove dirt and debris making the water more palatable and your filter more effective and longer lasting.

Does this Millbank Bag make water safe to drink?

No, it is a prefilter and clarifier only, you still need to take steps to disinfect the water afterwards.

Is this product made in the USA?

Yes, these are proudly made in Oklahoma, USA.

3 reviews for GB2 Millbank Bag Water Prefilter

  1. Dug North (verified owner)

  2. Patrick Martin (verified owner)

    No debris in my Grayle!

  3. Robert Miller (verified owner)

    All products, branded or not branded, are only produces that GB2 uses or developed. Therefore you can rest easy know the quality is at its finest. Combining this with my GRAYL make water treatment efficient and easy.

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