A solid choice for mixed conditions where regulating temperature matters, a put-on and leave-on layer. Rab says:Eliminate the need to stop and change layers as you close in on the summit, with this highly breathable and adaptable synthetic insulated jacket. It combinesPrimaLoft Gold Active insulation, which breathes and insulates through peaks and troughs of activity, with low-bulkThermicstretch fleece side panels that offer superb mobility and make the jacket easy to layer. The breathable yet wind-resistantPertex Quantum Airfabric deflects windchill while responding to your output, keeping you comfortable on tough ascents in mixed conditions. The result is lightweight, packable active insulation you can wear as a warm layer or technical outer, from the dawn start to the summit push.Our VerdictWarm when you need it and breathable when you dont, the Xenair Alpine Flex is built to withstand fast-moving mountain days.At 316g in a Medium, the Rab Xenair Alpine Flex is a carefully engineered piece of active insulation. It uses body-mapped PrimaLoft Gold Active in the core for warmth, with stretch fleece panels under the arms and sides to vent excess heat and facilitate movement. The result is a jacket that stays comfortable across a wide range of effort levels without constantly needing to layer up or down.The fit is trim, ideal over a light base layer, though it might feel snug if you prefer thicker layers underneath. The outer Pertex Quantum Air strike a decent balance between breathability and wind protection, and the overall feel is supple and quiet. Two hand pockets are well placed, and one acts as a stuff sack with a harness loop.- Reviewed by Ultralight Outdoor GearFeaturesBody mapped insulation with zoned areas of uninsulated panels to aid thermoregulationLightweight YKK VISLON centre front zip with chin guardPrecurved and articulated sleeves for improved fit and movement2 YKK zipped hand pockets, one of which doubles as an integrated stuff sack with harness attachment loopLightweight single sided rear hem adjustment with anti snag tetherSpecificationsSmall weighs: 304gMedium weighs: 316gLarge weighs: 341gXLarge weighs: 349gFit: SlimCentre back length (Size M): 72.5cm/28.5inchMaterial & Construction20D Pertex Quantum Air with fluorocarbon-free DWR (47gsm [2cfm])Thermic stretch fleece (215gsm) side panels20D recycled nylon (40gsm [10cfm])40gsm PrimaLoft Gold Active insulation (55% recycled content) throughoutThermic stretch fleece (215gsm) side panelsOuter: 100% Polyamide with Acrylic coating, Panels: 94% Polyester, 6% ElastaneLining: 100% Polyamide (Recycled), Insulation 55% Polyester (Recycled), 45% PolyesterHelp & advice:About RabRab Sustainability and ResponsibilityRecycled Content in Outdoor Gear

A solid choice for mixed conditions where regulating temperature matters, a put-on and leave-on layer. Rab says:Eliminate the need to stop and change layers as you close in on the summit, with this highly breatha