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Osprey Sirrus 36 vs REI Co-op Flash 45

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

No winner on weight yet. The recorded weights have not both been verified on the same basis. Size, included parts and single-item versus pair weights can differ. Check the linked sources before choosing a replacement.

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Spec Osprey Sirrus 36 REI Co-op Flash 45
Weight 1,220 g · 1.220 kg · 2.69 lb 1,190 g · 1.190 kg · 2.62 lb
Brand Osprey REI Co-op
Category Backpack Backpack
Osprey Sirrus 36
1,220 g

Women's ventilated 36L pack with AirSpeed back panel.

See it in your base weight → Full details →
REI Co-op Flash 45
1,190 g

Lightweight 45L versatile backpacking pack.

See it in your base weight → Full details →

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Osprey Sirrus 36 vs REI Co-op Flash 45: which should you buy?

The listed weights alone are not enough to choose between these products. Confirm the size, included parts and weight basis against each source; choose equipment for the function and fit you need.

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

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