Tough, streamlined, and built for serious weather, these trousers are ideal for big mountain days when performance matters more than weight. Rab says:Designed to accompany you on all-mountain hikes, scrambles, and ascents, these versatile waterproof pants take up minimal space in your pack, yet provide dependable protection in any conditions. Theyre engineered with 3-layerPertex Shield, deflecting hammering rain to keep you bone dry and making smooth progress towards the summit. With a part-elasticated waistband and full-length side zips, they’re quick to pull on over boots and crampons so theres no delay when a storm is closing in.Our VerdictThe Rab Firewall Mountain 3L Pants are an impressive combination of protection, function, and fit. At 355g for a Medium, theyre light for a full-spec shell trouser, and the 3-layer Pertex Shield fabric feels durable and breathable. The full-length side zips use triple pullers, meaning they can get over boots and help with ventilation during climbs.The cut is generous enough to layer over baselayers or trousers, but not baggy. Articulated knees and a long gusset make movement feel unhindered on steeper ground. I found the waistband comfortable and stable under a pack, though the absence of pockets does limit quick-access storage.- Reviewed by Ultralight Outdoor GearFeaturesLightweight, part elasticated waistband reduces bulk while providing support and structureLong length gusset at crotch and knee articulation for ease of movementFull length 2-way YKK AquaGuard side zips with internal storm guard and triple pullersDrawcord adjustable hem to accommodate different footwearSpecificationsSmall weighs: 344gMedium weighs: 355gLarge weighs: 374gXLarge weighs: 383gFit: RegularMaterial & Construction40D Pertex Shield 3-Layer construction waterproof technology with fluorocarbon-free DWR (133gsm) HH: 20,000mm/MVTR: 20,000 g/m2/24hrsMain Body: 100% Polyamide (Recycled) with Polyurethane membrane, Reverse: 100% PolyamideHelp & advice:Pertex Shield Technology ExplainedAbout RabChoosing a Waterproof JacketMVTR BreathabilityHydrostatic HeadRab Sustainability and Responsibility

Tough, streamlined, and built for serious weather, these trousers are ideal for big mountain days when performance matters more than weight. Rab says:Designed to accompany you on all-mountain hikes, scrambles, an