Sea to Summit’s new ultralight camping mat claims more comfort and less bulk with no weight penalty

Sea to Summit is lining up one of its most meaningful sleep-system updates in years with the launch of the Ultralight XR Sleeping Mat, a new model set to arrive as an early, REI-exclusive release on 1 February 2026.

Aimed at backpackers, fastpackers and weight-conscious travellers, the new camping mat focuses on improving real-world comfort and packability without increasing carry weight.

Sea to Summit says the Ultralight XR is 14% lighter than the previous Ultralight model, while also being 30% thicker and packing down 53% smaller.

Warmth has been pushed up as well, with an R-value of 3.6, making the new mat 16% more insulative than its predecessor.

For a mat that still weighs just 415g (14.6 oz) in Regular size, those numbers place it firmly in three-season territory without tipping into winter-mat bulk.

Stability, not just softness

The update centres around the revised take on Sea to Summit’s long-running Air Sprung Cell construction.

Rather than relying on horizontal or vertical baffles, the Ultralight XR uses 151 individual air-filled cells, each acting like a 'miniature spring'.

According to the brand, the updated dot-weld geometry helps the mat feel more planted on the ground, reducing the rolling or “teetering” sensation that can occur with traditional ultralight air mats, especially for side or restless sleepers.

Thickness now measures 6.5cm, which Sea to Summit positions as “true cushioning” rather than the floating-on-air feel some ultralight pads deliver.

The individual cells are designed to conform around shoulders, hips and the lower back, spreading pressure more evenly across the surface.

Warmth comes courtesy of updated ThermalCore insulation, which incorporates a TRM reflective layer to bounce infrared heat back toward the sleeper while also limiting internal air movement.

The result is improved thermal efficiency without adding synthetic fill or significant weight.

The Ultralight XR uses a hybrid 30/40D fabric paired with an extruded TPU laminate and Ultrafresh antimicrobial treatment, materials Sea to Summit says are backed by a decade-long track record.

The Sea to Summit Ultralight XR Sleeping Mat is available in Small, Regular and Large, with an MSRP of $149 for the Regular size, exclusively via REI at launch.