Sea to Summit Spark SP I vs Therm-a-Rest NeoAir XLite NXT Regular

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

Therm-a-Rest NeoAir XLite NXT Regular is the lighter option — 28 g lighter than the Sea to Summit Spark SP I (7% less weight). If grams matter to you, that is the one to beat.

Spec	Sea to Summit Spark SP I	Therm-a-Rest NeoAir XLite NXT Regular
Weight	397 g · 0.397 kg · 0.88 lb	369 g · 0.369 kg · 0.81 lb
Brand	Sea to Summit	Therm-a-Rest
Category	Sleep System	Sleep System

Sea to Summit Spark SP I

397 g

Ultralight 850-fill down sleeping bag rated to 25°C.

Full details →

Therm-a-Rest NeoAir XLite NXT Regular

369 g

Inflatable sleeping pad with R-value 4.5, 7.6cm thickness, Triangular Core Matrix baffles for warmth, and WingLock valve for fast inflation.

Check price Full details →

Sea to Summit Spark SP I vs Therm-a-Rest NeoAir XLite NXT Regular: which should you buy?

If saving weight is your priority, the Therm-a-Rest NeoAir XLite NXT Regular wins — at 369 g it is 28 g (7%) lighter than the Sea to Summit Spark SP I (397 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 sleep system page, or browse the full gear weight database.

More sleep system comparisons

Sea to Summit Spark SP I vs NEMO Equipment Tensor Elite Sleeping Pad Sea to Summit Spark SP I vs Therm-a-Rest NeoAir UberLite Sea to Summit Spark SP I vs NEMO Tensor Elite Ultralight Insulated Sea to Summit Spark SP I vs Zpacks Solo Quilt 20F Sea to Summit Spark SP I vs Nemo Tensor Ultralight Sea to Summit Spark SP I vs Zpacks Classic Sleeping Bag 20F