Start with your case size, engraved on the back of your watch. The 40, 41 and 42mm cases take a Small band; the 44, 45, 46 and 49mm cases take a Large. For Flex Link, that is the whole answer, because the adjustable clasp handles the rest. For One Flex, you also pick a loop number matched to your wrist. That takes two minutes, and the next answer covers it.

One Flex runs sizes 3 to 11 on the same scale as Apple's Solo Loop and Braided Solo Loop. If you already wear either, order your Apple number: a 7 there is a 7 here. If you're new to loop bands, use the printable sizing tool on the One Flex page (print at 100%, wrap it where you wear your watch), or measure your wrist just below the wrist bone with a tape. Our sizing guide walks through both methods with charts.

Take the smaller one. An elastic band can stretch to meet a wrist slightly beyond its number, but nothing can tighten a loop that runs big. Apple's own sizing tool gives the same instruction, and it holds here.

A little resistance pulling it over your hand, then flat and still on the wrist. The watch face shouldn't move when you raise your arm, and the band should sit close enough to keep the heart rate sensor against your skin. Too loose, it slides and breaks sensor contact; the elastic weave already provides the day-to-day give, so you don't buy room for it.

Stretch materials can lose recovery over time depending on their construction and use. One Flex gets its stretch from the woven metal structure rather than fabric fibers, and its recovery has been tested through repeated stretch cycles. Buy your measured size rather than sizing down “for later.”

Both bands fit Apple Watch Ultra 1–3, Series 4–11, and every SE generation. Choose Small for 40, 41, and 42mm cases and Large for 44, 45, 46, and 49mm cases, including the 49mm Ultra.

Yes, as long as you stay in the same case family. Bands are grouped, not model-locked: any Small band fits every case from 40 to 42mm, and any Large fits 44 through 49mm. The band on your Series 7 moves straight to a new Series 11.

Yes. The Ultra line is 49mm only, so order the Large band. Your loop number stays personal to your wrist; the case size doesn't change it.

They’re two answers to the same problem: metal bands that don’t move with you. One Flex is a single unbroken loop of woven 316 stainless steel with no buckle, clasp, or pin. You order your exact size, pull it over your hand, and it eases back to fit. Flex Link is a classic link bracelet with polished alloy links engineered to flex through their metal structure, plus an adjustable clasp that sets your base fit. Pick the look you want on your wrist. Both are built to move with you.

A stretch-fit band like One Flex comes in fixed loop sizes, so you choose the size that matches your wrist. The woven steel structure then gives slightly as your wrist moves through the day.

Flex Link works differently. Its adjustable clasp covers a wider wrist range, so you don’t need to choose an exact loop size. Just select the correct case size and make sure your wrist falls within the listed fit range.

If you want the fastest on-and-off and the cleanest profile, and you're happy to measure once, One Flex. If you'd rather skip sizing entirely, or you want the look of a traditional link bracelet under a shirt cuff, Flex Link. Same watch compatibility, same stretch.

Yes, both. One Flex's weave gives when your wrist flexes under load and settles back after; there's no clasp to fail because there's no clasp. Flex Link's clasp holds the fit you set, and the give in the links absorbs your movement instead of letting the band shift.

One Flex is woven from fine strands of 316 stainless steel, the corrosion-resistant grade the watch industry runs on. Flex Link is built from polished alloy links with flex engineered into the metal structure itself: the look and weight of a classic bracelet, engineered to move. Neither band relies on rubber or elastic thread for stretch.

That's the reason both bands exist. One Flex's open mesh drapes closer to fabric than a bracelet, breathes through long days, and has no clasp to press into your wrist at a keyboard. Flex Link's links lie flat and polished against the skin and move a few millimeters with your wrist, so it never clamps the way a rigid bracelet does.

That was the flaw of old spring-style expansion bands, whose segments opened gaps against the skin. These are different constructions: One Flex's weave is polished smooth and glides over skin and hair, and Flex Link's links are eased at the edges and move as one surface.

Sweat, rain, and handwashing are no problem; steel holds no sweat and the open mesh dries fast. After a pool or the sea, rinse the band in fresh water and dry it. Chlorine and salt are the only things worth washing off. Wipe down Flex Link after heavy sessions to keep its shine.

Warm water, a drop of mild soap, a soft cloth, air dry. Skip harsh chemicals and abrasives; the finish doesn't need them. The full routine, by material, is in our watch band care guide.

Write to service@eclipex.com within 30 days of delivery, and we'll exchange it for the right size. Your first One Flex size exchange is free — we cover the cost of shipping the replacement to you. Getting the fit right is the whole product, so we'd rather swap a band than have you wear one that doesn't fit.

No. Checking the fit at home is exactly what the 30-day window is for. Keep the packaging, keep the band in as-new condition, and a fit check doesn't count against you. Extended wear does, so decide within the first try-ons, not the first month.

30 days from the day your order arrives. Bands must be in as-new condition with original packaging. Once we inspect and approve your return, the refund goes back to your original payment method within 7 business days. For non-quality returns, the customer covers return shipping.

Inspect it on arrival and contact us straight away. We replace defective or incorrect items or issue a full refund at no cost to you, including return shipping.

Two years on manufacturing defects, on every band. If the weave, links, or clasp fails under normal wear, we make it right. Cosmetic wear from daily use isn’t a defect; a band that stops doing its job is.

Shipping is free on all orders! There are no minimum purchase requirements.

Orders are typically processed within 1–2 business days. Once shipped, delivery usually takes 7–10 business days, and your tracking number is emailed as soon as your package is dispatched.

We dispatch from warehouses in the US, UK, Germany, and China, whichever has your band closest to you.

Email service@eclipex.com within 1 business day of ordering. We process quickly, so once a package is fulfilled, we can't modify or redirect it; at that point the 30-day return process has you covered.

Visa, Mastercard, American Express, Discover, PayPal, Shop Pay, Google Pay, and Venmo. Checkout runs on Shopify, which is Level 1 PCI DSS compliant, the highest security certification in the payments industry, so your card details are encrypted and never touch our servers.

For EU customers, VAT is included in the order total. For other regions, local customs duties or import taxes may apply and are the customer’s responsibility. Requirements vary by destination.

Yes. For partnership programs and tiered pricing, see the wholesale page or write to support@eclipex.com.