SanDisk Ultra microSD 100MBs 128GB

SanDisk Ultra microSD UHS-I 128GB – SDSQUAR-128G

The SanDisk Ultra microSD UHS-I 128GB is a microSDXC memory card designed for everyday storage expansion across Android smartphones, tablets, dashcams, and compact cameras. Built on the UHS-I bus interface, the SDSQUAR-128G delivers sequential read speeds of up to 100MB/s — enough to transfer approximately 1,000 photos (averaging 3.5MB each) in under a minute when paired with a USB 3.0 card reader.

The card carries an A1 Application Performance Class rating, which mandates a minimum of 1,500 read IOPS and 500 write IOPS. In practical terms, this means Android apps stored or run directly from the card launch faster and experience fewer interruptions compared to unrated or lower-class alternatives. This is particularly relevant for users who have moved apps to external storage on their Android devices.

Speed Class and Bus Interface

The SanDisk Ultra 128GB is rated UHS Speed Class U1 and Speed Class 10, both of which guarantee a minimum sustained write speed of 10MB/s. This threshold is sufficient for continuous Full HD (1920×1080) video recording. However, it falls short of the V30/U3 ratings required for 4K UHD capture. Users shooting 4K video should consider the SanDisk Extreme line instead.

The card uses the UHS-I single-row bus, operating at a maximum theoretical bus speed of 104MB/s. The stated 100MB/s read speed represents near-ceiling utilisation of this interface. Write speeds are not published by SanDisk, though third-party benchmarks on the SDSQUAR-128G consistently record sequential write performance in the range of 40–65MB/s under controlled conditions.

Storage Capacity and File System

At 128GB, the SDSQUAR-128G uses the microSDXC format, formatted to exFAT by default. This allows individual file sizes beyond the 4GB FAT32 limit — relevant for users recording long uninterrupted video clips. Actual usable capacity is slightly below 128GB, as manufacturers calculate gigabytes using 1GB = 1,000,000,000 bytes, whereas operating systems report storage using binary (1GiB = 1,073,741,824 bytes).

Build and Environmental Ratings

Despite its compact form factor, the SanDisk Ultra microSD 128GB carries four environmental protection certifications:

• Waterproof — designed to survive immersion in water
• Temperature proof — tested across operating temperatures from -25°C to 85°C (-13°F to 185°F)
• Shockproof — resistant to drops and physical impact
• X-ray proof — safe to pass through airport security scanners without data loss

Storage temperature extends further, rated from -40°C to 85°C (-40°F to 185°F), making the card suitable for storage in cold or high-heat environments.

The card’s physical dimensions are 14.99mm (L) × 10.92mm (W) × 1.02mm (H), consistent with the standard microSD form factor. It weighs approximately 0.5g without the adapter.

Included Adapter and Companion App

The SDSQUAR-128G ships with a microSD-to-SD adapter, enabling use in full-sized SD card slots found in DSLR cameras, mirrorless cameras, and laptops. The adapter supports backward compatibility with SDHC and SDXC-enabled hosts.

Additionally, SanDisk provides the SanDisk Memory Zone app, available free on Google Play. The app allows users to view, access, and back up files stored across internal memory and the microSD card from a single interface. It also supports automatic file migration from device storage to the card when internal space runs low.

Compatibility

The SDSQUAR-128G is compatible with any device that supports microSDHC or microSDXC formats. This includes:

• Android smartphones and tablets running microSD-capable SoCs
• Dashcams recording in Full HD
• Chromebook devices (certified Works with Chromebook)
• Action cameras rated for Class 10 / U1 recording
• Nintendo Switch and Nintendo Switch Lite (when used with appropriate adapter)

Devices manufactured before 2008 may not support the SDXC standard and should be verified before purchase.

Warranty

The SanDisk Ultra microSD UHS-I 128GB is covered by a 10-year limited warranty from Western Digital (SanDisk’s parent company), subject to proof of purchase and applicable regional terms.

Who Is This Product Best Suited For?

• Android smartphone users upgrading storage — The A1 rating (1,500 read IOPS / 500 write IOPS) makes this card appropriate for running apps from external storage, not just media archiving. Users on Android devices with adoptable storage will see measurable app performance improvements over Class 10-only, non-A1 cards.
• Dashcam users recording Full HD footage — The U1 / Class 10 sustained write floor of 10MB/s covers the bitrate requirements of most 1080p dashcam systems. The -25°C to 85°C operating range also accommodates vehicle interior temperature extremes.
• Casual photographers and videographers — The 100MB/s read speed speeds up post-session card offloading to a computer. Users shooting JPEG stills and Full HD video will find the throughput adequate, though raw shooters at high burst rates may benefit from U3/V30-rated alternatives.
• Budget-conscious users needing reliable daily storage — The SDSQUAR-128G sits below the Extreme tier in SanDisk’s lineup without sacrificing daily reliability, four-way environmental protection, or the 10-year warranty.