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Acme Tornado 636 vs Ortovox Bivy Ultralight

Weight and specs compared for 2026 — and which one to choose.

Acme Tornado 636 is the lighter option — 186 g lighter than the Ortovox Bivy Ultralight (94% less weight). If grams matter to you, that is the one to beat.
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Spec Acme Tornado 636 Ortovox Bivy Ultralight
Weight 12 g · 0.012 kg · 0.03 lb 198 g · 0.198 kg · 0.44 lb
Brand Acme Ortovox
Category Safety Safety
Acme Tornado 636
12 g

Loud pealess emergency whistle. Standard SAR equipment.

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Ortovox Bivy Ultralight
198 g

Lightweight emergency shelter at only 7 oz. Insurance against unexpected weather conditions.

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Acme Tornado 636 vs Ortovox Bivy Ultralight: which should you buy?

If saving weight is your priority, the Acme Tornado 636 wins — at 12 g it is 186 g (94%) lighter than the Ortovox Bivy Ultralight (198 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest safety page, or browse the full gear weight database.

More safety comparisons