Rab/Ultrasphere 4.5 Sleep Mat

The Optimal Solution for Minimalists



Rab is a brand founded in 1981 by British climber Robert Carrington, producing highly reliable, high-quality items designed for extreme cold environments and alpine climbing worldwide. The company is especially renowned for its expertise and meticulous detail in down and synthetic insulation products, which are also its roots.

The Ultrasphere 4.5 is a featherlight air mat that combines the ultra-lightweight material TILT with an offset air chamber structure that prevents heat loss. It is ultra-lightweight (370g), high-performance (R-value 4.3), and has a minimized pack size (18×9cm), making it the optimal solution for minimalists.

The newly developed tapered mummy shape pursues a balance between ultra-lightweight and high performance. By staggering the positions of holes between horizontally arranged air chambers, it significantly reduces internal air convection, providing excellent heat retention. It also accurately distributes body pressure, and its 8cm thickness offers a very comfortable sleeping experience. Inside, it features a special two-layer TILT reflective film called Thermo Ionic Lining Technology, derived from metal, which reflects heat emitted from the body, greatly reducing radiant heat loss. This allows for a reduction in the structure needed to maintain a certain warmth, achieving an astonishing balance. The soft-touch fabric also reduces sleeping bag slippage. It is equipped with a thin, two-way valve and comes with a large pump sack for quick inflation. The stuff sack, which can be opened and closed from the side, makes packing and unpacking easy. Due to its tapered mummy shape, when combined with the Insuration Sheet 00, it reduces condensation from sleeping bags that extend beyond the mat and adds insulation, allowing for a lighter experience.


- R- VALUE 4.3
- 20D recycled polyester TPU coating
- Fluorocarbon-free DWR durable water repellent finish
- Equipped with a special 2-layer TILT reflective film derived from metal, which reflects heat emitted from the body, significantly reducing radiant heat loss.
- A unique structure in which the holes in the partition walls of the chamber inside the lightweight mat are shifted to significantly reduce air convection inside the mat and maintain warm air.
- Light weight with tapered mummy shape
- Low-profile 2-way valve allows for easy inflation and deflation
- Comes with pump sack
- Comes with repair kit
- Roll-away stuff sack included
- Light gray color
- Rab domestic genuine product


Pack size: approx. 18 x 9 x 9cm
Weight: 370g
R-VALUE : 4.3
Material: Fabric: 20 denier recycled polyester TPU coating
Attachments: stuff sack, pump sack, repair kit



Product code 09965-43-417