Icebreaker
Icebreaker 200 Oasis Long Sleeve Crewe (men's, size M)
- Weight: 6/10 How much it adds to your pack.
- Warmth: 7/10 How much the fabric insulates next to your skin. Heavier fabric is warmer and slower to dry.
Three-season hill days and wild camps, as a base layer or as a sleeping top
- Weight
- 217 g (M)
- Fabric weight
- 200 g/m²
- Fibre
- Merino
- Merino
- 100%
Where to buy
Alpinetrek £79.16 In stock. Price for the colour shown (list £89.95). Free delivery from £85. The cost under £85 is not on the page.
View at shop: AlpinetrekIcebreaker £89.99 In stock. Free delivery. Black, size M. Free standard delivery over £40; free returns.
View at shop: IcebreakerTiso £90 In stock. Free delivery. Blue (Atlantis). Free delivery over £50.
View at shop: TisoPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Weight
From maker's figures 6/10How much it adds to your pack. 6: A bit better than average.
217 g in men's size M (Icebreaker UK, matched by Tiso) is in the 200–239 g band.
Warmth
From maker's figures 7/10How much the fabric insulates next to your skin. Heavier fabric is warmer and slower to dry. 7: Better than most.
200 g/m² is in the 190–239 g/m² band. The figure is Icebreaker's own: its fabric numbering is the fabric weight in g/m² (its 2020 page for this same style says so, and its base layer guide puts midweight tops at around 200 g/m²). Alpinetrek lists 200 g/m² too. It is the maker's class, not a lab reading.
What reviewers say (out of 10)
Ratings marked * are from reviews and are not part of the trip score. They are reviewers' scores, not our own measurements. How we score
Comfort*
Reviewers' average 9/10How soft and comfy it feels next to your skin.
4 reviews on comfort, e.g. "The 100% Merino wool is stretchy and soft next to the skin.".
Odour*
Estimate: only 2 reviews about odour (fewer than the 3 we need, so never above 8) 8/10How fresh it stays after days of wear; higher is fresher.
2 reviews on odour, e.g. "doesn’t smell after two weeks’ wear, including sleeping in it".
Drying*
Reviewers' average 8/10How well it wicks sweat away and dries.
5 reviews on drying, e.g. "This had the fastest drying time of any 100% Merino wool layer and dried as quickly as some of our lightweight synthetic options!".
In short
Good for
- Three-season hill days and wild camps, as a base layer or as a sleeping top
- Multi-day trips without washing: 100% merino that testers wore for days and weeks without it smelling
- Winter days in the hills worn under a fleece or insulated jacket
- Walkers who want a plain crew with no zip and shoulder seams that sit clear of rucksack straps
Strengths
- 100% merino, and a mid-weight 200 g/m² fabric that keeps its warmth when damp
- Soft and stretchy: three tests rate comfort high
- The Great Outdoors' tester reports no smell after two weeks of wear, sleeping in it
- Gusseted underarms, flatlock seams, offset shoulder seams and a drop tail hem
- Icebreaker calls it its best-selling base layer
Weaknesses
- 217 g in size M, heavier than a light merino top such as a 150 g/m² one
- Pure merino is less hard-wearing than blends with nylon: expect eventual thinning at cuffs and elbows, and a slightly stretched neck over years
- CleverHiker found it slower to dry than most layers it tested (OutdoorGearLab found it the fastest-drying pure merino it tried), and merino is slower than synthetic in general
- Cut short in the arm and body for tall people (OutdoorGearLab)
- Slim, close fit: it cannot go over another layer (TGO), so size up if you want room
- Cold gentle machine wash only; Icebreaker says do not tumble dry
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (10)
- Icebreaker UK: Men's 200 Oasis Thermal Top (long sleeve crewe): price £89.99, weight size M 217 g, 100% merino
- Tiso: Icebreaker Men's 200 Oasis Long-Sleeve Crewe Thermal Top (weight size M 217 g, price and stock)
- Alpinetrek: Icebreaker 200 Oasis L/S Crewe (material thickness 200 g/m², reference size L 252 g)
- Icebreaker: base layer guide (lightweight layers 75–175 g/m², midweight around 200 g/m², heavyweight 260 g/m² and above)
- Icebreaker (archived 2020 page, same style 104365): 100% merino, gusseted underarms, offset shoulder and flatlock seams; its fabric numbers are the fabric weight in g/m²
- OutdoorGearLab: Icebreaker 200 Oasis Review (men's, tested and abrasion-tested)
- The Great Outdoors: Review: Icebreaker 200 Oasis LS Crewe (Chris Townsend)
- CleverHiker: Icebreaker Merino Oasis 200 Review (men's M, Colorado Trail thru-hike)
- Icebreaker UK customer reviews: 200 Oasis Thermal Top (936 reviews, 4.8 out of 5, 556 verified buyers; on the maker's own store)
- Alpinetrek customer reviews: Icebreaker 200 Oasis L/S Crewe (65 reviews, 4.8 out of 5, tick-box tags)