Perfect hiking layer
"Perfect breathable layer for my hike"
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$90.00
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$90.00
This item's price has been updated recently to ensure you get the best value.
Last priced at -
A soft and stretchy long sleeve T-shirt for everyday comfort and layering, the Siren Long Sleeve Sweetheart features a slim fit and our corespun merino wool blend fabric.
Good for:

83% Merino Wool/ 12% Nylon/ 5% Elastane, Exclusive of decoration
Machine wash warm. Wash inside out with like colors. Do not use softener. Do not bleach. Do not tumble dry. Line dry in shade. Warm iron. Do not iron print and accessories. Do not dry clean.
Fit
Slim
The Siren is a lightweight next-to-skin layer. It’s crafted from 150gm merino jersey corespun fabric that’s lighter than most other fabrics we use, and is made with a snug, slim fit that works perfectly as a cosy piece beneath your other layers. Our Siren tees fit tighter than other tees in our range, just size up if you like a looser fit.
Overall rating: 4.5929823 / 5 from 570 reviews.
This long sleeve T-shirt offers a flattering slim fit and is made from a soft merino wool blend fabric, praised for its comfort and versatility as a base layer. Customers appreciate its stylish appearance and beautiful color, though opinions on the size vary.
Review topics: ["fit","size","weight","problem","quality","delivery","looks","value","fabric","material","feel","price","top","layer","wear","colour","neck","warmth","sleeves","works","style","comfort","weather","shirt","winter","arms","stretch","base layer","shape","medium"].
"Perfect breathable layer for my hike"
— Vp (5/5)
"For years I wore uniqlo heat tech shirts, but those would get sweaty and stretch out over time, and I would get too hot in them. This shirt is much nicer on the skin as it never made me sweaty and stays fresh for much longer. I lost my shirt and was devestated—and have since bought a new one. I like that the cut of these shirts are low enough that they’re usually not visible underneath other items, and if I do end up taking a layer off I think the neckline is really beautiful and flattering. I do wish the shirts were a bit longer so they could stay tucked in better. I bought a size small (my usual size, with a chest size of 34b) and it fits well, fitted without being tight."
— Lucia S. (5/5)
"Warm stretchy comfortable and moisture wicking. Used 4 days straight on ski adventure and it didn’t stink! Love this thing."
— Anonymous (5/5)
"I live in Icebreaker base layers 9 months a year. I live in a ski town and the warmth breathability and skin feel is the best!!"
— Anonymous (5/5)
"Well made. & super comfy. Staple in our place for everyday wear."
— Anonymous (5/5)
"Exactly what I wanted. I wear this on days that have temps ranging from 40 F to 65 F and I never feel cold or hot. Minimal odor retention great fit. I will be buying more. No complaints. Great price. Great for everyone from beginner to expert. Cold to hot this is the top for you and the whole family. I will be buying other models from Icebreaker! Minimal sweating and stank what else could you ask for?"
— Anonymous (5/5)
"Nice top but I do not like it as much as I like the crew neck."
— LORIE R. (4/5)
"Comfortable, snug, base layer. Very happy with it."
— Margaret R. (5/5)
"Perfect fit and weight"
— Julie G. (5/5)
"Superbe!"
— Lisette L. (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 | |
|---|---|---|---|---|---|---|
| Bust | 30-32 | 32-34 | 34-37 | 37-40 | 40-42 | 42-45 |
| Arm length | 30 | 30.25 | 30.5 | 30.75-31 | 31-31.25 | 31.25-31.5 |
| Waist | 24-26 | 26-28 | 28-30 | 30-33 | 33-36 | 36-39 |
| Hips | 33-35.5 | 35.5-38 | 38-40 | 40-42.5 | 42.5-45 | 45-48.5 |
| XS | S | M | L | XL | XXL | |
|---|---|---|---|---|---|---|
| Bust | 76-82 | 82-88 | 88-94 | 94-100 | 100-107 | 107-116.5 |
| Arm length | 76-76.5 | 76.5-77 | 77-77.5 | 78-78.5 | 78.5-79 | 79-79.5 |
| Waist | 61-66 | 66-71 | 71-77 | 77-84 | 84-91 | 91-101 |
| Hips | 84-90 | 90-96 | 96-102 | 102-108 | 108-114 | 114-123 |
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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