Super warm and cosy baselayer
"Great base layer in charcoal. Grey is a little sheer but fine if you wear with a bra underneath. Hugs all the right places."
Merino Blend
£70.00
This item's price has been updated recently to ensure you get the best value.
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£70.00
This item's price has been updated recently to ensure you get the best value.
Translation missing: en.products.product.price.price_tooltip
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.
Model measurements
Height: 179cm / 5'10". Waist: 62cm / 24". Anya is wearing size S.
Slim Fit
A snug, close-to-body fit for low bulk layering.
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.
Standard delivery: free for all order over £ 40. Delivery in 5-7 days, from Monday to Saturday, during working hours.
Please visit our Delivery page and find out more about the ways in which you can receive our products.
You have 30 days from delivery to follow our quick and easy return procedure.
Overall rating: 4.599034 / 5 from 621 reviews.
The 150 Siren Sweetheart T-shirt is praised for its soft and comfortable feel, flattering neckline, and excellent quality. Customers love the versatile long sleeves and the perfect fit, making it ideal for layering. The beautiful color options and flattering look add to its appeal.
Review topics: ["fit","size","weight","length","weather","quality","fabric","problem","material","looks","wear","value","delivery","feel","comfort","colour","top","layer","sleeves","packs","neck","warmth","style","price","winter","arms","stretch","shirt","medium","shape"].
"Great base layer in charcoal. Grey is a little sheer but fine if you wear with a bra underneath. Hugs all the right places."
— Mark (5/5)
"Nice top but I do not like it as much as I like the crew neck."
— LORIE R. (4/5)
"Perfect for base layering under sweaters with low or wide necklines. No visible logo/brand name, which I prefer."
— Alaina M. (5/5)
"Superbe!"
— Lisette L. (5/5)
"You won't be disappointed it's fabulous to wear and washes so well. Im going to buy more as I keep going for this top to wear underneath clothing or its fabulous on its own."
— Kiwi (5/5)
"Had less than a year for an Icebreaker product and it developed a whole. Icebreaker customer service claims it's either wear and tear OR it's been miss-used. So will do nothing about the issue."
— Unhappy S. (1/5)
"Love it! Will buy it again"
— Gege (5/5)
"Great under anything from blouses to sweaters to provide extra warmth. Fits close so no extra bulk under clothes."
— Northeaster (5/5)
"The green Color is just perfect, and perfect fit. Thank you!"
— Montrealuser (5/5)
"To me, snow colour should mean white, this is definitely beige!"
— Stretch (2/5)
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.
| XXS | XS | S | M | L | XL | XXL | |
|---|---|---|---|---|---|---|---|
| Bust | 27.5-30 | 30-32.5 | 32.5-34.5 | 34.5-37 | 37-39.5 | 39.5-42 | 42-46 |
| Arm length | 30 | 30.3 | 30.3 | 30.5 | 30.8 | 31 | 31.3 |
| Waist | 22-24 | 24-26 | 26-28 | 28-30.5 | 30.5-33 | 33-36 | 36-40 |
| Hips | 31-33 | 33-35.5 | 35.5-38 | 38-40 | 40-42.5 | 42.5-45 | 45-48.5 |
| XXS | XS | S | M | L | XL | XXL | |
|---|---|---|---|---|---|---|---|
| Bust | 70-76 | 76-82 | 82-88 | 88-94 | 94-100 | 100-107 | 107-116.5 |
| Arm length | 75.5-76.5 | 76.5-76.75 | 76.75-77 | 77-77.5 | 77.5-78.25 | 78.25-79 | 79-79.5 |
| Waist | 56-61 | 61-66 | 66-71 | 71-77 | 77-84 | 84-91 | 91-101 |
| Hips | 79-84 | 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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