Rab Ultrasphere 4.5 Arcteryx Vertex Alpine GTX The Proton is the ideal

The Proton is the ideal hiker or climbers jacket for when the valley bottom is hot but higher and more exposed terrain is much cooler

With a compact

an exterior daisy chain that lets you lash it to the outside of bags and a large

which serves as an effective manual thermostat for rapid ventilation when the intensity peaks or the sun hits the south face

followed by a quick dip in a river after

Rab Ultrasphere 4.5 Arcteryx Vertex Alpine GTX The Proton is the idealRab's TILT heat reflective technology which bumps up the warmth while adding a negligible amount of weight. The Ultrasphere 4. 5 is designed to be used in conjunction with Rab's Mythic Ultra 120 Modular sleeping bag, but is actually a great, superlight and warm mat on its own. Inside the Ultrasphere 4. 5 is two layers of Rab's TILT reflective film which reduces radiant heat loss without adding weight or bulk and does not rustle at all like other heat