Rab Ultrasphere 5

The Rab Ultrasphere 5 is a high-performance ultralight sleeping mat engineered for fast-paced mountain missions where thermal efficiency and minimal pack weight are non-negotiable. Weighing just 345g (Regular) and delivering an impressive R-value of 5.5, it offers exceptional warmth-to-weight performance for cold conditions. Its advanced construction combines two layers of heat-reflective TILT technology to reduce radiant heat loss, alongside innovative offset air chambers that trap warmth internally without bulky insulation. The result is a featherlight yet highly supportive 8cm thick mat suited to bikepacking, thru-hiking and multi-day alpine objectives. Compact, efficient and thermally optimised, it is built for serious fast & light exploration.

TILT (Thermo Ionic Lining Technology): A radical, heat retaining tech that works like an emergency blanket reflecting heat back towards your body, while maintaining breathability and comfort. Boosting thermal efficiency, it keeps you warm when the temperature plummets.

Features:
Ultra-lightweight
R-value of 5.5 for cold mountain conditions
Dual-layer TILT reflective technology reduces radiant heat loss
Offset air chamber construction improves internal heat retention
8cm thickness for comfort and ground insulation
Tapered mummy profile to reduce bulk
Soft, lightweight 20D fabric
Two-way valve for fast inflation and deflation
Inflation sack included
Roll-away stuff sack with repair kit

Specifications:
Weight (regular): 345g / 12.2oz
Shape: Tapered Mummy
Thickness: 8cm
R-Value: 5.5
Activities: Fast & Light Adventures, Trekking, Mountaineering

Regular:
Dimensions: 183cm x 51cm x 8cm
Packed Size: 15cm x 9cm (5.9in x 3.5in)

Regular Wide:
Dimensions: 183cm x 64cm x 8cm
Packed Size: 19cm x 9cm (7.5in x 3.5in)

Long Wide:
Dimensions: 196cm x 64cm x 8cm
Packed Size: 19cm x 9cm (7.5in x 3.5in)