SOL Thermal Bivvy vs SPOT Gen4

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

SPOT Gen4 is the lighter option — 21 g lighter than the SOL Thermal Bivvy (12% less weight). If grams matter to you, that is the one to beat.

Spec	SOL Thermal Bivvy	SPOT Gen4
Weight	170 g · 0.170 kg · 0.37 lb	149 g · 0.149 kg · 0.33 lb
Brand	SOL	SPOT
Category	Safety	Safety

SOL Thermal Bivvy

170 g

Reusable emergency bivvy. Warmer than mylar alternatives.

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SPOT Gen4

149 g

One-way satellite tracker with SOS capability.

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SOL Thermal Bivvy vs SPOT Gen4: which should you buy?

If saving weight is your priority, the SPOT Gen4 wins — at 149 g it is 21 g (12%) lighter than the SOL Thermal Bivvy (170 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.

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