HydraPak 42mm Filter Cap vs HydraPak UltraFlask Speed 600ml
Weight and specs compared for 2026 — and which one to choose.
Lightweight fast-flow filter cap that threads onto 42mm bottles, removing bacteria and cysts for hiking and travel.
Soft-sided water bottle at 2 oz (57g) designed for running hydration vests and ultralight backpacking with collapsible design.
Building a pack? Add either one to your HikeLoad list, or drop its weight into the base weight calculator, and see what it does to your total weight.
HikeLoad is reader-supported. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Learn more.
HydraPak 42mm Filter Cap vs HydraPak UltraFlask Speed 600ml: which should you buy?
On weight these two are identical (57 g), so your decision comes down to features, fit and price. Check the full details and current price for each above.
See where both rank against everything else in this category on the lightest hygiene page, or browse the full gear weight database.