Amazon Basics microSDXC Memory Card with Full Size Adapter, A2, U3, Read Speed up to 100 MB/s, 128GB, Black
Quick take
This Amazon Basics 128GB microSDXC card targets faster real-world performance with A2 (application performance) and U3 (sustained video) ratings, plus read speeds up to 100 MB/s. It includes a full-size SD adapter, making it easy to use in cameras and laptops. The main caveat is compatibility, because some devices have maximum supported microSD capacities, so you should confirm 128GB is supported.
Pros and cons
Pros
- A2 + U3 rated for responsive app behavior and smoother high-bitrate video on compatible devices.
- Up to 100 MB/s read speed and designed for 4K and Full HD use cases.
- Includes a full-size SD adapter for easier camera and computer transfers.
- Built for travel and outdoor use, with shock resistance and IPX6 water resistance.
Cons
- Not all devices support 128GB microSD cards, so compatibility needs to be checked first.
- Speed depends on your device and workflow, so you may not always see the top advertised read speed.
- It is a microSDXC card, so it is not meant for devices that require a different card type.
What buyers think
Buyer-review evidence for this card emphasizes reliable day-to-day performance, with multiple mentions of smooth transfers and dependable operation for photos, videos, and expanded storage on phones and other devices. Reviewers also commonly connect the card’s real-world behavior to its stated A2 and U3 positioning, noting fast enough read performance for their workflows and no recurring issues like corruption or errors during typical use. There is also consistent appreciation for the included full-size SD adapter, especially for offloading files to cameras and laptops.
What it is, and why the A2 and U3 labels matter
This is a 128GB microSDXC card designed for modern storage needs where you are not just capturing media, you are also running apps or expecting responsive performance. Two performance classes are key here:
- U3 (UHS-I Video Speed Class V30): geared toward higher-bitrate recording and sustained write performance, which is important for 4K video and burst-mode capture on compatible devices.
- A2 (Application Performance Class): intended to improve random read and write behavior for faster app loading and smoother multitasking when your device supports microSD app adoption or similar features.
In practical terms, this makes the card a good fit for phone storage expansion, action and surveillance-style use, and any workflow where a basic Class 10 card might feel slower.
Performance and speed expectations
The card is rated for up to 100 MB/s read speed, and it is also listed with a media speed figure of 60 MB/s. Reviews align with that general expectation, with users reporting speeds in the neighborhood of the advertised read performance when measured in their device setups. As with any microSD card, the exact speed you experience can vary based on your phone or camera, the adapter (if applicable), and what you are doing (copying large files vs. many smaller files).
4K video, dashcams, and photo-heavy workflows
The U3 rating and 4K-ready positioning are aimed at users recording high-bitrate video, including scenarios like dashcams, security cameras, and devices that handle continuous recording. Buyers who used it in camera-like roles reported smooth operation without dropped frames or buffering issues during their typical setups, though results will still depend on your device’s recording settings and compatibility.
Durability you can actually plan around
If your storage needs involve travel or outdoor use, this card is rated for shock resistance, IPX6 water resistance, and extreme temperatures (−10°C to +80°C). It is also described as resistant to X-rays and magnetic fields, which can matter for travel and certain environments. While no memory card is indestructible, these specs suggest Amazon Basics designed it for rougher real-world handling.
Storage capacity and the “usable capacity” reality
Like most flash storage, the card’s labeled capacity is not exactly what you will see in your device because of formatting and the way operating systems calculate storage. For this model family, usable-capacity expectations are provided for multiple sizes (for 128GB, the usable amount is listed as ≥116GB). If you are planning storage for video or app installs, it helps to budget based on usable capacity rather than the marketing number.
Compatibility checklist before you buy
Before purchasing, confirm:
- Max supported microSD capacity: the card is marketed as compatible with Nintendo Switch (not Switch 2), but in general you should verify your exact device supports 128GB microSDXC.
- microSDXC support: if your device only supports microSD or microSDHC, it may not work correctly.
- Your device’s file and recording requirements: if you shoot 4K or higher-bitrate video, match the card class to your device’s expectations.
Who should buy this card
- Phone and tablet users who want expanded storage and faster app-style performance if their device supports it.
- Videographers and camera users capturing 4K-ready footage or burst-mode photos on compatible devices.
- Dashcam and security camera owners looking for sustained-performance behavior with U3 support.
- Travelers and outdoor users who value IPX6 water resistance and shock-resistant design.
Who should skip it
- Buyers with older devices that cap microSD capacity below 128GB or do not support microSDXC.
- Users who only need basic storage for occasional photos and files, since you may not need A2/U3 class performance.
- Anyone requiring guaranteed maximum speeds regardless of their device and workflow, because real-world performance depends on compatibility and usage.
Verdict
The Amazon Basics 128GB microSDXC card is a practical, value-oriented choice if you want more than just storage space. With U3 support for higher-bitrate video, A2 for app-oriented performance on compatible devices, and an included full-size SD adapter, it works well for phone storage, camera workflows, and continuous recording use cases. Make sure your device supports 128GB microSDXC first, and you will be set up for the kind of reliable performance buyers describe.
FAQ
Is this microSD card compatible with Nintendo Switch?
It is marketed as compatible with Nintendo Switch (not Nintendo Switch 2). You should still confirm your device’s maximum supported microSD capacity before buying 128GB.
Will I get the full 100 MB/s read speed?
You may see read speeds close to the advertised figure in device setups that can sustain it, but real performance can vary depending on your host device, the file types you copy, and whether you are using the included SD adapter.
What does A2 mean on this microSDXC card?
A2 is the Application Performance Class. When used in a compatible device that supports app-related performance features on microSD, it is intended to improve random read and write behavior for faster app loading and more responsive multitasking.
Is it good for 4K video recording?
It is positioned for 4K and Full HD capture, with U3 video speed support (Video Speed Class V30) intended for sustained performance. Your actual results will depend on your device and recording settings.
Does it come with an SD adapter?
Yes, it includes a full-size SD adapter, which makes it easier to use with cameras and laptop SD slots.
How much usable storage should I expect from 128GB?
Because of formatting and how storage is calculated, the usable amount will be less than the labeled capacity. For the 128GB size in this series, usable capacity is listed as at least 116GB.
Is the card durable enough for outdoor use?
It is rated for shock resistance, IPX6 water resistance, and temperatures from −10°C to +80°C, which makes it a reasonable option for travel and outdoor environments.
Specifications
| Product Title | Amazon Basics microSDXC Memory Card with Full Size Adapter, A2, U3, Read Speed up to 100 MB/s, 128GB, Black |
|---|---|
| Category | Electronics > Computers & Accessories > Computer Accessories & Peripherals > Memory Cards > Micro SD Cards |
| Brand | Amazon Basics |
| Manufacturer | Amazon |
| Model Name | LSMICRO128GU3 |
| Model Number | LSMICRO128GU3 |
| Item Weight | 8.02 Grams |
| Color | Black |
| Flash Memory Type | Micro SDXC |
| Memory Storage Capacity | 128 GB |
| Compatible Devices | Camera, Drone, Laptop, Smartphone, Tablet |
| Additional Features | Magnetic Proof |
| Read Speed | 100 Megabytes Per Second |
| Media Speed | 60 MB per second |
| Hardware Connectivity | microSDXC |
| Secure Digital Association Speed Class | Class 10 |
| Item Dimensions L x W | 1.69"L x 0.3"W |
| Item Dimensions D x W x H | 0.04"D x 0.59"W x 0.43"H |
| Warranty Type | Limited |
| UPC | 840095874021 |
| Mfr Part Number | LSMICRO128GU3 |
| Unit Count | 1.0 Count |
| Warranty Description | 12 months |
Available variants
Style
- 512GB
- 64GB(2 pack)
- 1TB
- 128GB
- 256GB
Capacity
- 512 GB
- 64 GB (2pack)
- 1 Tb
- 128 GB (Pack of 2)
- 256 GB
- 128 GB
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