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Platypus
GravityWorks 4.0L Replacement Reservoir Kit

3.65 out of 5 stars
20 Reviews
Current price: $65.56 Original price: $81.95
20% off
Color:One Color

Size:

Quantity

Only 2 In stock


GravityWorks 4.0L Replacement Reservoir Kit

You're leading a field camp this summer and the last thing you want to do is take care of a bunch of college kids with giardia. You have the GravityWorks filtration system, but could do with a bit more capacity, so you've grabbed the Platypus GravityWorks 4.0L Replacement Reservoir Kit. Your previous dirty reservoir was getting a bit grungy, so you get to start over with a brand-spanking-new bag, and now you can store an additional four liters of fresh clean waters for your thirsty undergrads. While this kit does not include the actual filter and filtration tube, these replacement reservoirs come in handy when you need additional capacity or a couple backups—just in case.


Details

  • Replacement reservoirs for Platypus GravityWorks filtration system
  • Dual-layer laminate provides food-grade, taste-free interior
  • 8 liter total capacity supplies backpacking groups with clean water
  • Disconnect fittings interchangeable with any GravityWorks system
  • Item #CAS008D
Material
plastic
Volume
4L each
Valve
quick-disconnect fitting
Dimensions
3.25 x 9.5in
Recommended Use
backpacking, hiking, travel
Manufacturer Warranty
limited

What do you think about this product?

Overall Rating

3.5 based on 20 ratings

Review Summary

1 Stars - 3 reviews
2 Stars - 2 reviews
3 Stars - 2 reviews
4 Stars - 5 reviews
5 Stars - 8 reviews

View

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5 out of 5 stars

July 24, 2025

The bag is sturdy and

The bag is sturdy and light. I like this material more than I remember liking the original- I think it's a bit thicker. I lost that bag years ago though so it's hard to make a direct comparison. Regardless, solid replacement bag, would recommend.

Reed C.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

5 out of 5 stars

July 15, 2025

I like the system but

I like the system but there are light weight materials that are waterproof that would be better than the current plastic bag.

Lee C.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

5 out of 5 stars

July 11, 2025

It's great! Went with a

It's great! Went with a 6L so I could filter more water faster

Austin H.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

1 out of 5 stars

July 8, 2025

Too small

Did not have the 6L . . . Always out of stock on everything. . .

Henry H.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

4 out of 5 stars

November 30, 2024

Zip close

The zip close doesn’t close anymore. Otherwise the system works great! I live my gravity works.

Kathy D.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

5 out of 5 stars

November 12, 2024

GravityWorks™ water filter

My most valuable piece of backcountry/emergency preparedness equipment!

Mike H.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

5 out of 5 stars

November 7, 2024

I’ve used these for years.

I’ve used these for years. I’ve never had a problem—except when a mouse chewed into one. Otherwise, they’ve served me well

J S.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

4 out of 5 stars

March 5, 2024

Great products - PLEASE SELL THE CLEAN TANKS AND CAPS!!!

Awesome system!!! The clean bags double as really great longer distance water containers (IE kayaking for a few days with no fresh water available..) can you pretty please sell them in 4L and 6L with caps??? Much more trustworthy than the "Platy bag" with the seal along its length. You might even make the bags so the caps attach with a tether, they're very easily to lose in the field.

Conrad
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

5 out of 5 stars

January 29, 2023

Love my GW

I have used Gravity Works for years and they have never failed me. The extra weight is worth it.

J S.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site

4 out of 5 stars

November 8, 2022

Difficult to dry

Hands down the best water filter I’ve ever used in 30 years of drinking from backcountry streams and lakes. It’s miraculously easy to set up, walk away and the next time you glance at it you have four liters of clean, clear, and tasteless water. My only gripe is why can’t the Clean reservoir have the same wide zip-loc opening as the Dirty reservoir to allow easier drying and cleaning? The little soda cap opening on the Clean reservoir doesn’t allow enough air exchange to permit proper drying in less than 2 days, promoting mildew growth and more frequent cleaning, which is also a pain because of the small opening. So close to five stars, but not quite.

Tim G.
a Cascade Designs brand site

Originally reviewed on a Cascade Designs brand site