Pioneered by three bored engineers/mountaineers living in Seattle in 1972, Therm-a-rest’s game changing inflatable pads have been at the cutting edge of backcountry comfort for as long as they’ve existed. Though much innovation has taken place in the decades since—most notably the introduction of NeoAir, a patented design involving a matrix of air chambers that boosts heat retention by 50%. I recently had the opportunity to put the new SpeedValve equipped NeoAir XLite MAX SV mattress to the test over several ultralight backpacking trips in the Sierras.
The SpeedValve uses the Bernoulli Principle to achieve much more efficient inflation, promising two to three times faster inflation than non-SpeedValve version for a mere 5oz increase (the long version I tested weighed in at 1lb 5oz). In short, you blow into the opening at the top from about six to eight inches away, and the pressure differential pulls in the surrounding air to inflate the mattress with significantly fewer breaths.