OMM Halo Pant Review

Overview

The OMM Halo Pant is a minimalist waterproof overtrouser built for mountain marathon racers and fastpackers who want rain protection without the weight penalty of a traditional shell. At 80g, it’s built to disappear in your pack until you actually need it, trading durability and features for an almost absurdly low weight. It’s best thought of as emergency/mixed-conditions insurance rather than a four-season workhorse — a distinction that matters a lot when deciding whether these are right for you.

Quick heads-up before you shop: OMM has changed the name of all their Halo products to Wisp, though only the name has changed — the products themselves have not. So if you see “Wisp” pants with identical specs, that’s the same garment.

Key Specs

Spec	Detail
Weight	80g (men’s; women’s runs ~70–85g depending on size)
Fabric	PointZero H2O 2-layer waterproof
Waterproof rating	10,000mm hydrostatic head
Breathability	10,000 g/m²/24hr
Seams	Fully taped
Packed size	Tennis ball
Combined weight w/ Halo Smock	190g
Closures	Elasticated waist, Velcro ankle tabs
Storage	Internal stuff pocket

Performance

The headline feature here is obviously the weight, and it’s real — a men’s large came in at 88g for one reviewer’s pair, less than a third of what a conventional Gore-Tex overtrouser with side zips and a hard-wearing build typically weighs. That number tracks closely with OMM’s own claimed 80g, and it’s genuinely one of the lightest fully-waterproof pants on the market.

Where it gets interesting is how OMM got there. There’s no side-zip, no built-in gaiter, and the whole design is stripped to a minimalist build — no side zips or gaiters, though you do get Velcro tabs at the ankles for securing over shoe cuffs, plus articulated knees, taped seams, and an elastic waistband. The stuff pocket is a nice touch for keeping the pants from disappearing into the bottom of your pack, though the packed bundle doesn’t always stuff away completely, and the little flap at the opening could be more secure — a minor gripe, but worth knowing before you rely on it to keep sand or grit out.

On the fabric itself, the PointZero H2O material feels notably thin in hand — one long-term field tester described it as “incredibly light and almost papery,” while still rated to a decent 10,000mm hydrostatic head. That papery feel is the give-and-take of the weight savings: it’s not something you want to bushwhack through gorse in.

The best real-world data point I found comes from a thru-hiker who wore the Halo Pants across a 517-mile route through the Pyrenees. Over three or four spells of bad weather, including one stretch lasting several days, he wore the Halo Pants for 30–40 miles of hard trail, and they performed excellently. That’s meaningful mileage for a pant this light, and it suggests the fabric holds up better than its feel might suggest — at least on foot trails rather than technical scrambling.

The caveat, and it’s an important one for durability-conscious buyers: overtrousers this light were never going to be a main pair for general hillwalking or backpacking because they simply aren’t durable enough for long-term hard use — they’re designed for mountain marathons where every gram counts, which makes them ideal for ultralighters heading to hot countries with generally settled weather, where you rarely need waterproofs except for the odd thundery downpour. In other words, these reward hikers who pack them as a “just in case” layer rather than an everyday-wear rain shell.

Breathability is rated at 10,000g/m²/24hr, and combined with the featherweight fabric, that seems to hold up during high-output efforts like running or scrambling, per multiple retailer listings echoing the same articulated-knee, freedom-of-movement design intent. I didn’t find independent lab data or long-term breathability complaints in user reviews, so treat the 10k rating as a solid but manufacturer-sourced number rather than field-verified.

Fit runs snug — several retailers note the women’s version in particular fits smaller than comparable brands, so sizing up is a common recommendation. Value is strong: at roughly £75, this sits well below what you’d pay for a Gore-Tex equivalent, even accounting for the reduced feature set.

Pros & Cons

Pros

• Genuinely ultralight — 80g claimed weight, verified in the high-80s to low-90s range by independent testers
• Packs to tennis-ball size, easy to carry as always-in-the-pack insurance
• Held up over 30-40 miles of hard multi-day trail use in a real thru-hike test
• Fully taped seams and 10,000mm HH rating for genuine waterproof (not just water-resistant) performance
• Excellent value relative to heavier Gore-Tex alternatives

Cons

• Papery-feeling fabric with no built-in gaiters or side zips — not meant for bushwhacking or scrambling on rock
• Internal stuff pocket flap isn’t fully secure
• Not durable enough for daily hillwalking or backpacking use as a primary shell
• Sizing runs small, especially in the women’s version
• Limited independent long-term durability data beyond a handful of field reviews

Who Should Buy This

The Halo Pant makes the most sense for mountain marathoners, fastpackers, and thru-hikers heading through generally settled, warm-weather regions who want emergency rain protection without carrying a heavier shell “just in case.” If your trip involves sustained days of foul weather, heavy bushwhacking, or scrambling over abrasive rock, you’ll want something burlier. But as a lightweight insurance policy for the occasional downpour, it’s hard to beat the weight-to-protection ratio here.

Verdict

The OMM Halo Pant delivers on its core promise: real waterproof protection at a weight that barely registers in your pack. It’s not a do-everything rain pant, and you shouldn’t expect Gore-Tex durability from 80 grams of fabric, but for the ultralight and thru-hiking crowd carrying it as backup rather than a daily driver, it’s one of the better options out there. I’d rate it a 7.5/10 — outstanding for its intended niche, with the caveat that you need to buy into that niche.