Designed in Japan
Shop NowNice top but I do
"Nice top but I do not like it as much as I like the crew neck."
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$85.00
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$85.00
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: 4.6013074 / 5 from 612 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","length","weather","quality","fabric","problem","material","looks","wear","value","delivery","feel","comfort","colour","top","layer","neck","price","warmth","sleeves","style","shirt","arms","winter","stretch","works","medium","shape"].
"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)
"J'adore ce haut. J'en achète 2-3 par an et je les mets autant pour dormir qu'en couche de base. Chandail mince mais qui procure la petite chaleur nécessaire parfaite et qui se met bien sous n'importe quel pull. La coupe est très belle et flatteuse. Je recommande vivement!"
— Moi (5/5)
"Superbe!"
— Lisette L. (5/5)
"I was disappointed when this arrived and I realised that I had bought a non 100% wool product. However, I have worn and been won over as it has none of the drawbacks of other mixed products I have worn. Very comfortable and flattering fit. I would not buy a mixed product again (except by mistake) but I am very happy with this top."
— Jean (5/5)
"This is the first time that I brought an ice breaker product and I am very happy. I bought the heavier weight and this one, and I really like the neck line which is invisible undershirts. It is a very light layer and while it is warm, it's also discreet. You can tell the difference in heat between this and the 260 icebreaker."
— Rosinky (5/5)
"I love the neckline and figure hugging fit of this tee. I wear it alone but it would also work great as an undershirt during cooler months. The feel isn't as silky soft as some of my other Icebreaker clothing but I don't find it itchy at all."
— Lynnie (5/5)
"This is a great base layer, the perfect size (great online sizing tool, Icebreaker!) and keeps me warm under work shirts/tops. The extra fine merino is lovely to wear, not scratchy or uncomfortable"
— SHB (5/5)
"Everyday use and under sweaters when it cold"
— Llama (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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