
SanDisk Ultra Dual Drive 256GB USB-C Black
Score: 71/100
Techkey USB Flash Drive 128GB
Score: 79/100Rankings

The Techkey 128 GB MFi-certified flash drive offers versatile three-in-one connectivity and a rugged metal build, delivering fast USB 3.0 speeds. Its main drawbacks are the mandatory iOS app and the lack of detailed size/weight specs. Ideal for travelers and iOS users who need a durable, cross-platform backup solution.

The SanDisk Ultra Dual Drive 256 GB combines USB-A and USB-C connectors in a retractable design, delivering up to 150 MB/s read speeds and a 5-year warranty. It lacks waterproofing, hardware encryption, and detailed write-speed specifications, which may limit its appeal for power users. Best suited for mobile users who need quick cross-platform file transfers and a compact, high-capacity drive.
| Attribute | ![]() | ![]() |
|---|---|---|
256 GBbest | 128 GB | |
150 MB/sbest | 80 MB/s | |
— | 40 MB/sbest | |
| ↓ lower better | 9.1 gbest | — |
5 yearsbest | 2 years |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Storage(1) | ||
Storage Capacity (GB) | 256 GB | 128 GB |
Performance(1) | ||
Read Speed (MB/s) | 150 MB/s | 80 MB/s |
Connectivity(2) | ||
USB Version | USB 3.1 Gen 1 | USB 3.0 |
Interface | USB | USB 3.0, Lightning, USB-C |
General(2) | ||
Warranty (years) | 5 years | 2 years |
OS Compatibility | Android, iOS | iOS, Android, macOS, Windows |
Build & Design(1) | ||
Dimensions (L×W×H) (mm) | 38.1x20.7x9.4 mm | 3.94 x 0.03937 x 5.43 inches mm |
Features(1) | ||
Hardware Encryption | false | true |

Products in the top-left offer the best value (high score, low price).

Professional reviewers highlight the high read-speed performance and the convenience of dual connectors, but note the lack of detailed write-speed information and limited durability features in the base model.
Everyday users appreciate the convenience of quickly offloading phone media and the portable design, while some express disappointment with slower real-world speeds and wish for better ruggedness or security features.

“USB 3.0 speed is very fast on computers.”

“NWT, ideal for travel.”



Professional reviewers highlight the drive's very fast USB 3.0 performance and the convenience of having Lightning, USB-C and USB 3.0 ports in a single, rugged package, while noting that the mandatory BLANBOK+ app on iOS adds a setup step and that independent testing is limited.
Everyday users praise the drive for quick, one-click backups and seamless cross-platform file transfers, especially while traveling, and they value the durable metal build; no major complaints are repeatedly mentioned beyond the required app for iOS.