Basement - Thermarest Trail King SV Large Air Mattress

R-Value: 0.32 / Dimensions: 196 x 63 x 6.3cm / Packed Size: 33 x 18cm
Weighs 982g (excluding bag)
Code: SS17145
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Thermarest's Trail King SV mats are a hybrid construction offering a warm, comfortable easy to use sleeping mat that's only slight downside is it's pack size.

Thermarest says: The Fastest Self-Inflating Backpacking Mattress

By combining our SpeedValve technology with AirFrame Construction, we’ve created a backpacking mattress that inflates in a matter of seconds. Plus, thanks to the auto-reversing SpeedValve, the mattress deflates at remarkable speeds. This unprecedented ease-of-use is fused with 2.5 inches of ultra-supportive loft and an R-Value of 1.8, making the Trail King SV a reliable and three-season mattress designed to save you precious time in the backcountry. Stuff sack included.

Air Frame Construction

Air Frame Construction is really quite simple. It uses alternating channels of foam and air to create a skeleton of foam within an air mattress. The resulting hybrid of technologies offers the best of both - the high-loft comfort and compressibility of an air mattress, and the convenience, added stability and support of a self-inflating mattress

Thermal Foams

Thermal Foam is our proprietary, solid-core foam. While it may look like just foam, we have spent decades researching with our supplier, evolving this most basic element of our self-inflating pads. The resulting foam is made in the USA, and optimized for the best balance of light weight, lasting durability, and uniformity of support.

Thermarest pioneered the self-inflating mat for camping, open cell foam sandwiched between two sheets of nylon expands and draws air into the mat to inflate it. Such mats offer reasonable comfort and insulation but were superceded in recent years by insulated airbeds - offering smaller packed sizes, thicker mats which are more comfortable and higher levels of insulation.

Thermarest's Trail King SV mattresses combine both technologies to create a mat that is thick enough to be comfortable and warm but with enough foam inside to be self-inflating and relatively stable compared to an airbed, so if an airbed is a bit bouncy for you the Trail King could be the answer.

Although its technically self-inflating all mats need a helping hand at the end of the inflation process and with Thermarest's Speed Valve technology this takes no effort whatsoever.

Weight and packed size make takes this out of the realm of backpackers - especially the packed size, but its an ideal base camp mat when your priorities are ease of use and comfort.

- Reviewed by Ultralight Outdoor Gear

  • Supportive Loft: AirFrame construction offers 2.5 inches (6.3 cm) of high-loft support
  • Fast Inflation: SpeedValve technology combined with self-inflating foam creates swift inflation
  • Faster Deflation: Auto-reversing SpeedValve deflates mattress in a flash


  • Weight: 982g
  • Dimensions: 63 x 196cm
  • Thickness: 6.3cm
  • Packed size: 33 x 18cm
  • R value: 1.8 (US) / 0.32 (SI)
  • Top fabric type: 50D print polyester
  • Bottom fabric type: 75D polyester


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