Therm-a-Rest NeoAir Pump Sack Review

Overview

The NeoAir Pump Sack is a 40-liter waterproof stuff sack with a valve fitting sewn into its base. Fill it with a couple of scoops of air, roll the top, and squeeze that air into a NeoAir pad, no lungs required. It suits backpackers who want dry inflation and a multi-use bag, and its main trade-off is a few ounces of dedicated weight for a job a pair of lungs does for free. The sack has been discontinued, though it still turns up bundled with some pads and on the secondhand market.

Key Specs

Spec	Detail
Volume	40 L
Dimensions	13 in x 27 in (33 cm x 69 cm)
Weight	2.7–3.4 oz (77–95 g) depending on production run
Valve compatibility	Wing Valve (WingLock) only; not compatible with Classic Valves
Original MSRP	US $29.95
Status	Discontinued

Performance

Inflation. The sack’s selling point is volume. Raymond Estrella, a long-time reviewer at BackpackGearTest.org, has used pump sacks bundled with many winter pads over the years. The ones he describes ranged from merely adequate to maddeningly weak, and nearly all were too small. He judged the NeoAir Pump Sack the first to get the size right. Once he practiced a couple of times at home, he got fast fills. Two bags of air is the standard recipe for a NeoAir pad, and the 13 x 27 inch envelope holds enough to make that work. The one problem he reported was the plug popping off the valve.

Dry air. The pad-longevity argument for pump sacks is moisture: breath puts humidity inside a down-free but still insulation-bearing pad, and that matters most when nights drop below freezing. Estrella tested the sack on a three-day, 34-mile North Country Trail loop with sleet and a low of 19°F. Not everyone is convinced the effect is large. One Backpacking Light forum poster who weighed his pad after a week on the trail saw no change from moisture. His case for a pump sack rested on cold-weather insulation and on the breath it saves. At 10,000 feet, after a big climb, blowing up a mattress by mouth is an easy way to get light-headed. That altitude argument gets more support from owners than the moisture one does.

As a stuff sack or liner. The wide opening is what makes the secondary uses practical. Outdoor Gear Lab’s testers, reviewing the XLite NXT, noted that the sack’s large mouth lets it pull double duty as a pack liner or oversized stuff sack. The original sack is built from waterproof 70-denier ripstop nylon, with a drawcord and cord-lock at the top and a grab handle protecting the valve plug at the bottom. That fabric is tougher than the 20-30D shells common in the ultralight category, and it shrugs off a damp pack.

As a seat. Therm-a-Rest pitches a Jembe-style camp seat: slide a rolled NeoAir into the sack and inflate. The idea has fans, but Estrella never tried it, since only a layer of nylon would sit between the pad and any burr on the ground. That caution is sensible for a pad that costs more than $150.

Compatibility. The sack mates with the Wing Valve (WingLock) found on later NeoAir pads. It will not work with Classic Valves, so owners of older pads should check the valve before buying a used one. Backpacking Light posters have noted that the fit on some pads is snug enough that DIY tinkering helps.

Pros & Cons

Pros

• Large 40 L volume fills a pad in a couple of squeezes
• Keeps breath moisture out of the pad
• Saves lung effort at altitude
• Doubles as a waterproof stuff sack or pack liner
• No batteries to carry or charge

Cons

• Roughly 2.7–3.4 oz of added weight; heavier than a Micro Pump-style electric pump at 2.3 oz
• Wing Valve only; will not inflate Classic Valve pads
• Technique matters; the plug can pop off if squeezed carelessly
• Less suited as a seat than the marketing suggests
• Discontinued, so buyers must hunt for stock

Who Should Buy This

Cold-weather and shoulder-season hikers with a Wing Valve NeoAir will get the most from it, as will anyone camping at altitude, where mouth inflation is a chore. It is also a sensible pick for hikers who already carry a waterproof liner and can let this one fill that job. Gram-counters in summer who tolerate breath inflation can skip it. So can anyone with a Classic Valve pad, who needs a different pump.

Verdict

The NeoAir Pump Sack does what it says: it inflates a Wing Valve NeoAir quickly with dry air, and its large opening makes it a useful pack liner. At about 3 oz it earns its place on cold or high trips and is optional the rest of the year. Buyers should confirm their pad’s valve type first.