This new jacket from Rab has a lot to like about it from a performance perspective, but there are also some very admirable aspects on the sustainability front too. That’s why it’s one of only a select few items this year to make it into our Greener Gear Guide.
Rab Latok Mountain Gore-tex Pro: The Top Line
Rab know what they’re doing when it comes to waterproof clothing. This is a jacket that’s designed for very harsh conditions, but it’s also surprisingly light and packable too. It’s one of the first waterproof jackets out there to use the latest version of Gore-tex Pro fabric, which contains no PFAS chemicals.
Pros: Durable and protective but still light and packable, good eco aspects, lots of mountain-focussed details.
Cons: Some might be disappointed by its lack of handwarmer pockets.
Buy the Rab Latok Mountain Gore-tex Pro: £480 at Ellis-brigham.com
How I Tested It
I’ve managed to test this throughout spring and summer this year, wearing it during a number of forays into the Welsh mountains while surveying routes for a new guidebook I’m working on. I’ve also used it on wet walks around my local area and on a sunny trip to the Lake District’s fells where it was mainly the breathability that was tested and not the weatherproofing!
I haven’t managed to test it out in harsh winter conditions yet, but I’ll come back and update this review when I have. My hunch is that it’ll be well up to the task there.
Materials
A couple of years ago, Gore-Tex launched a big overhaul of their fabrics by developing new fluorine-free durable water repellent (DWR) treatments to maintain waterproof performance while eliminating toxic substances. This phasing out hadn’t reached the top spec Gore-Tex Pro fabrics – until now. Rab are in fact one of the first brands given access to the new fluorine-free Gore-Tex Pro membrane, thus marking a major step toward fully sustainable, high-performance waterproof gear.

What’s the new Gore-tex Pro fabric like then? Well, the short answer is that it’s a bit different to the previous version. First of all, it feels lighter, less crinkly and rustly than its predecessor. It’s hard to give a quantifiable assessment of the durability, but I’d say it feels no less durable. I’d say the same goes for the weatherproofing as well – it’s a reassuringly bombproof layer to help you handle the nasty stuff.
The main difference is in the levels of aftercare required. Things are about to get a bit nerdy here so buckle up.
Older versions of Gore-Tex Pro used powerful, longer-chain (C8) PFAS chemicals that helped waterproof jackets repel moisture more effectively and for longer periods. Over the last decade, the industry shifted to short-chain PFAS, specifically C6-based fluorocarbon compounds, which are generally less environmentally persistent while maintaining strong water-repellent performance.