Rank #8 in Best 128GB SD Cards 2026: 10 Ranked, and Three Adverts That Contradict Themselves
Gigastone 128GB SDXC 4K Pro Series Card
Price and rating as shown on Amazon when we collected them. Both change.
The Gigastone 4K Pro Series is a 128GB SDXC card, listed as A1, V30 and Class 10, priced at £49.99 and rated 4.5 out of 5 from 4,982 ratings. It comes in at number 8 in this guide.
The speed story on this card is one number and one gap. The product name promises "Transfer Speed Up to 100MB/s", and the spec table files that same 100MB/s under Read Speed — so the figure the title leads with is a read figure, and the advert states no write speed at all. The field labelled Media Speed reads 90 with no unit attached, so the listing never says whether that is 90MB/s, 90x or something else. Two smaller quirks: the model number and the UPC are printed as the same string, and the star breakdown that comes with the listing adds up to exactly 100 across its five bars — 4, 1, 6, 14 and 75 — against a stated 4,982 ratings, so one of those two figures is a percentage rather than a count.
Everything on this page is taken from the Amazon listing as it stands. We have not tested this card ourselves.
How those 4,982 ratings break down
An average hides its own shape. This is the spread behind the 4.5 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £49.99 for the 128GB 4K Pro Series |
|---|---|
| Rating | 4.5 out of 5 from 4,982 ratings |
| Read Speed (as listed) | 100MB/s |
| Media Speed (as listed) | 90, with no unit given |
| Write Speed | Not stated anywhere in the advert |
| Interface and classes | UHS-I SDXC, Class 10, V30, A1 |
| Warranty (as listed) | Limited, 5 years; EU spare part availability 5 years |
| Model Number (as listed) | 804272755701, the same string as the UPC |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“The product arrived very quickly in suitable packaging. Upon opening, the first thing I noticed was the build quality. It looks like a premium product. It felt sturdy/lightweight in the hand, which gave a great first impression.I've been using this Gigastone 128GB memory card for a couple of days now. Setting it up was simple just slot it in my new camera & away you go! In terms of performance, it handles long 4k videos with ease & uploads really quickly which is much better than my previous old one.Overall, I would recommend this to anyone looking for a memory card for any Christmas gifts like Camera's & action Cameras.”
Verified purchase“Brilliant value. Came in a wee plastic box for travelling / storage. Will be buying from them again.”
What it is up against
The rivals it was ranked against in Best 128GB SD Cards 2026: 10 Ranked, and Three Adverts That Contradict Themselves.
Questions people ask
How fast is the Gigastone 128GB 4K Pro Series?
The advert quotes a transfer speed of up to 100MB/s in the product name and files the same 100MB/s as Read Speed in the spec table, so the headline figure is a read figure. It gives no write speed, so nothing in the listing says how fast this card records.
What does the Media Speed figure of 90 mean?
The spec table lists Media Speed as 90 with no unit attached. The listing does not say whether that is 90MB/s, 90x or another kind of rating, so we can only report it as it is printed.
Is the Gigastone 128GB card suitable for 4K video?
Gigastone markets it as A1, V30 and Class 10 for 4K UHD video, and the model name is 4K Pro Series. V30 is the video speed class the advert claims; the listing provides no sustained write figure to check that claim against.
Does the card come with a case?
Yes. The advert's second bullet states that it comes with 1 mini case alongside the card.
What warranty does the Gigastone 128GB card carry?
The advert states a 5 year limited warranty from the manufacturer, and the spec table repeats "Limited" as the Warranty Type with EU spare part availability of 5 years.
Is the card protected against water and magnets?
The advert describes it as waterproof, temperature-proof, x-ray-proof, shock-proof and magnetic proof, and the spec table repeats magnetic proof, water proof and x-ray proof.
Comments
Reader comments are not checked against the manufacturer's claims above.
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