Iron Flask 40 oz
Top PickWhat We Like
- Keeps drinks cold throughout a full day outdoors.
- Offers three interchangeable lids for straw, spout, or wide mouth drinking.
- Delivers solid build and insulation at a budget-friendly price.
Worth Noting
- Plastic lids can break with rough handling
- Straw lid may leak if not seated correctly.
- Lid
- 3 lids: straw, spout, wide
- Capacity
- 40 oz
- Material
- 18/8 Stainless Steel
- Insulation
- Double-wall, cold 24h / hot 12h
Read the full review
The Iron Flask 40 oz comes with three lids (straw, spout, wide mouth) and double-wall stainless steel insulation that keeps water cold for 24 hours — all for under $20. It suits campers and hikers who want a large capacity bottle with drinking options, but the plastic lids may break under rough handling and the straw lid can leak if not sealed properly.
Tip: Hand wash the lids and keep the straw lid fully closed when packing to minimize leaks.
Bottom line: For campers and hikers who want flexibility and capacity without spending much, the Iron Flask delivers — just be gentle with the lids.