

VERSATILE ACTIVE INSULATION.
Lightweight Polartec® Power Grid™ fleece that matches insulation with breathability. A mid layer for cold hikes and climbs, or a standalone layer for dry, cool, low wind days.
SIEGE TECH FLEECE HALF ZIP
£110
FEATURES
IN THE FIELD & REVIEWS
- Quality
- Fit
- Warmth
- Design
- Weight
- andy e.Verified BuyerI recommend this productRated 5 out of 5 stars2 months ago5 Stars
Outstanding quality… both in materials and design…a bold statement but probably the best fleece I’ve ever owned.
Was this helpful? - NormanVerified BuyerI recommend this productRated 5 out of 5 stars2 months ago5 Stars
Great item for everyday life. Warm and breathable yet lightweight. Perfect!
Was this helpful? - RICHARD L.Verified BuyerI recommend this productRated 5 out of 5 stars2 months ago5 Stars
True to size feels great
Was this helpful? - ANDYI recommend this productRated 5 out of 5 stars2 months ago5 Stars
Functional, stylish and bombproof quality…ThruDark’s ‘raison d'être’
Was this helpful? - Grant W.Verified BuyerI recommend this productRated 5 out of 5 stars2 months ago5 Stars
Bought two now - for cycling all day I haven’t seen anything that comes close to these tops. They wick the heat and keep you warm in equal measure. Uncanny material, I don’t seem to be able to destroy them. They don’t smell either; you can wear them for days and somehow they stay fresh. If you were doing an expedition or something where you can only take minimal gear, these are priceless, I kid-you-not.
Was this helpful?
TRENDING
SIEGE TECH FLEECE HALF ZIP
Lightweight fleece
£110
SIEGE TECH FLEECE HOODED
Hooded lightweight fleece
£135
SIEGE TECH FLEECE HOODED
Hooded lightweight fleece
£135
SIEGE TECH FLEECE HALF ZIP
Lightweight fleece
£110
TRENDING
SIEGE TECH FLEECE FULL ZIP
Lightweight fleece
£130
SIEGE TECH FLEECE HOODED
Hooded lightweight fleece
£135
SIEGE TECH FLEECE FULL ZIP
Lightweight fleece
£130
SIEGE TECH FLEECE FULL ZIP
Lightweight fleece
£130
NEW
ARETE FLEECE
Quarter zip fleece
£65
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PHALANX HOODED FLEECE
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£240
MOUNTAIN PRO TECHNICAL MID LAYER
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£150
RESTOCK LANDED
HERITECH MOORLAND FLEECE
Polartec® fleece
£180
SIEGE TECH FLEECE HOODED
Hooded lightweight fleece
£135
NEW
CENTURION JACKET
Polartec® fleece soft shell
£260
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ARETE FLEECE
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FORWARD HOODIE
Lightweight zip-up hoodie
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FAQS
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Should you not be satisfied with your order, you have 30 days from the date of delivery to return it for an exchange, full refund, or gift voucher credit.
All exchanges are free using our returns portal. Please note that returns for a refund will have a shipping fee deducted: £5.00 for UK orders, and approximately £10.00 for international orders (depending on the country) to cover the cost of return postage.
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At ThruDark we are constantly striving to deliver a better service to our customers. With Klarna we can now offer all UK and international customers Buy Now, Pay Later with Klarna using their pay in 3 instalments with 0% interest and no fees.
With Clearpay we can now offer UK, US, Australian and Canada customers to pay in 4 instalments interest-free over 6 weeks.
Please note: Klarna & Clearpay is unavailable for pre-order items.
Learn more on our partnership with Klarna & Clearpay -
Mainland UK
Free standard delivery is available on orders of £175 or above.
Free next-day delivery is available on orders of £350 or above.
For orders below these thresholds, a range of delivery options is available at checkout.
Estimated timeframes are provided by the couriers and should be used as a guide only.
Channel Islands & UK Offshore
Delivery options for Guernsey, Jersey and the Isle of Man are shown at checkout, with timeframes provided as courier estimates.
Shipping Method Cut-off Times
Delivery estimates apply to orders placed before the cut-off times listed below.
Orders placed after the cut-off on Fridays will be dispatched on the next working day.
- Royal Mail Standard – 4:00 PM, Monday to Friday
- Royal Mail Express – 2:30 PM, Monday to Friday
- DHL Express – 2:00 PM, Monday to Friday
- FedEx – 2:00 PM, Monday to Friday
Additional Information
- Delivery timeframes are estimates only and may vary by location or during busy periods.
- All estimates refer to working days (Monday to Friday, excluding UK bank holidays).
- Next-day services may take 1–3 working days for Highlands and Northern Ireland.
- Order values are shown in GBP and will be converted to your local currency at checkout.
- Any additional delivery or customs charges are the responsibility of the customer.
- If Royal Mail is unable to deliver to a business address, it may be due to address accuracy, access issues, safety concerns, delivery holds, or local service disruptions. Please check for service updates or contact customer support if needed.
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All international shipping amounts will be calculated at checkout.
Delivery times may vary depending on shipping location and during busier periods.
All estimates are based on working days, which are Monday to Friday, excluding UK bank holidays.
Next-day services are estimated at 1-3 days for Highlands and Northern Ireland.
International orders are shipped Delivered Duty Paid (DDP) with import duties and taxes covered — except orders to the United States, where taxes are calculated at checkout.
Please note: we do not reimburse any additional delivery or customs fees.
All amounts are based on GBP and are converted to your local currency at checkout.
We will not reimburse customers who pay any additional delivery or customs fees.
All international shipping amounts will be calculated at checkout -
We provide tracking numbers on all orders once fulfilled and dispatched by our warehouse team. These can be used to follow the progress of your delivery and in some cases to change address or delivery details if required. Please see below for links to track and manage your parcel with our respective couriers:
- Royal Mail - https://www.royalmail.com/track-your-item
- DHL - https://www.dhl.com/gb-en/home/tracking.html?locale=true
*If you need to change the delivery address on your shipment please use the DHL app or manage the shipment online with Royal Mail. Unfortunately, our Support team is unable to amend shipping addresses or make any other changes to your order once placed.*
- Royal Mail - https://www.royalmail.com/track-your-item



















