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Shop NowMy new favorite! Thick and
"My new favorite! Thick and cozy."
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$250.00
This item's price has been updated recently to ensure you get the best value.
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$250.00
This item's price has been updated recently to ensure you get the best value.
Last priced at -
A heavyweight merino wool base layer top designed to keep you warm and comfortable on the coldest of days, the 300 MerinoFine™ Polar Long Sleeve Half Zip features our premium, luxuriously soft ultra-fine merino fibres that are incredibly soft next to skin.
Good for:

100% Merino Wool. Exclusive of Decoration.
Machine wash cold gentle cycle. Wash with like colors. Do not use softener. Close all fasteners before washing. Do not bleach. Do not tumble dry. Dry flat in the shade. Cool iron. Do not dry clean.
Key product measurements
Back High Point Shoulder to Hem: 73cm/28.5in (Based on size M)
Fit
Slim
Overall rating: 4.6923075 / 5 from 26 reviews.
Review topics: ["fit","weight","quality","colour","thickness","shirt","works","base layer","buy","clothing"].
"My new favorite! Thick and cozy."
— Sean P. (5/5)
"Quality product, warm and perfect fit. Is great over a thermal and/or under a jacket so works well for layering also. So all-in-all, I am very happy with this purchase."
— Rocket (5/5)
"It is very comfortable and soft on the skin. Does exactly what it says on the tin - keeps you warm in very cold conditions."
— Mango (5/5)
"Good quality clothing, fast delivery, warm and cosy"
— Al (5/5)
"Good weight fabric and incredibly soft. Almost silk like feeling against the skin. Very comfortable and warm so far and looking forward to seeing how well it performs over time. Really impressed so far."
— D (5/5)
"I was really looking for a heavy base layer and purchased these top & bottoms immediately. The quality is still obvious. Warm, but still breathable, the Size medium is just a bit snug on my 6'0"" frame but still fine. I just completed a cold weather exercise the military where it was -15C to -23C. This is what I wore all weekend."
— Sarge (5/5)
"Use it for cold weather hiking and biking. It is warm and cozy. The zipper does not work properly as I need to twitch it left/right along the upper end to make it zip all the way. The zipper is anything but smooth as the other icebreaker items including a cardigan are, that i own. For a size large it needs to be longer to work optimal as an undershirt. The material is superb."
— Portalite (4/5)
"Enfin la bonne épaisseur 300 pour les courses à -25 degrés celsius. Je le porte avec une veste hybride icebreaker. Combinaison parfaite . Chaud, respirant, doux, confortable . Je mesure 6p 2po pèse 220 lbs taille 35 et le xl est parfait"
— Pop (5/5)
"Having other 300 and for the price. . . This is just a glorified 260. I think this is as far as my run with icebreaker will go."
— Lu C. (1/5)
"I wear icebreaker everyday but love it especially for my remote arctic whitewater paddling trips. Never fails, always warm, fast drying and comfortable. Love icebreaker ??"
— Eyeguy (5/5)
Find the size that fits you best based on people just like you.

Use the chart below to determine your size. If you’re between two sizes, order the smaller size for a tighter fit or the larger size for a looser fit. If your measurements for chest and waist correspond to two different sizes, order the size indicated by your chest measurement for tops and your hip measurement for pants.
| XS | S | M | L | XL | XXL | XXXL | |
|---|---|---|---|---|---|---|---|
| Neck | 12-13 | 13-14 | 14-15 | 15-16 | 16-17 | 17-18 | 18-19 |
| Chest | 33-35 | 35-37 | 37-40 | 40-43 | 43-46.5 | 46.5-49.5 | 49.5-52 |
| Arm length | 33.5 | 33.5-34 | 34 | 34-34.5 | 34.5 | 34.5-35 | 35-35.5 |
| XS | S | M | L | XL | XXL | XXXL | |
|---|---|---|---|---|---|---|---|
| Neck | 32-34 | 34-36 | 36-38 | 38-41 | 41-43 | 43-46 | 46-49 |
| Chest | 84-89 | 89-94 | 94-102 | 102-110 | 110-118 | 118-126 | 126-134 |
|
Arm length |
85-85.5 | 85.5-86 | 86-86.5 | 86.5-87 | 87-88 | 88-89 | 89-90 |
Our three different fits - slim, regular, and relaxed - ensure that when worn together, layers move and breathe like a single garment.



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