SanDisk SDDD3-256G-G46 | 256GB Ultra Dual Drive m3.0 for Android Devices and Computers – microUSB, USB 3.0

Free up space on your Android Phone (Requires device with micro-USB port and On-The-Go (OTG) support. See official SanDisk website for list of compatible devices.)
Back up photos, videos, and contacts
Retractable design with dual microUSB and USB 3.0 connectors
High-speed USB 3.0 performance with up to 150MB/s file transfer from drive to computer (Write speeds lower and varies by capacity. Micro-USB port with USB 3.2 Gen 1 / USB 3.0 support required. Based on internal testing; performance may be lower depending upon host device, interface, usage conditions and other factors. 1MB=1,000,000 bytes.)
SanDisk Memory Zone application (available on Google Play) lets you easily manage your photos and videos (Download and installation required. Set up automatic backup within app settings. See SanDisk Memory Zone website for details.)