[DETAIL] When you can't detect the original speed! Please choose this original Sandisk card reader! This card reader is specially used to read the Sandisk memory card. Click the card reader to learn more! ↑↑↑Click to buy Sandisk Mobilemate USB 3.0 Reader Use the Sandisk Mobilemate USB 3.0 Reader plugged into a USB 3 port. The type of reader you use for speed tests makes a huge difference. When you used one of the cheap card readers（USB2.0）, the maximum speed was only about 25 MB/s for each card. So make sure you use a reader with a good controller for the test. Otherwise, The speed will not reach the speed of the card itself. So it is not the SD microSD cards that are to blame for the lower speeds, but the "old" hardware that does not support the newer technology. FOR A1 / A2 CARDS, A NEW CARD READER IS REQUIRED IN ORDER TO APPROXIMATELY REACH THE SPECIFIED VALUES! ●Tips: If the speed detection of the memory card decreases, it is related to the performance of the computer configuration and the performance of the card reader! Please switch to a higher-end computer and a higher-end card reader test! Thank you About capacity: 8GB=approximately 7GB-7.5GB 16GB=approximately 14GB-15GB 32GB=approximately 28GB-30GB 64GB=approximately 58GB-60GB 128GB=approximately 115GB-119GB 256GB=approximately 230GB-238GB 512GB=approximately 450GB-500GB 1TB=approximately 880GB-980GB This is calculation difference between manufacturer(1GB=1000MB) and our PC(1GB=1024MB),please Google Memory card capacity to get more information. ●Tips: If the speed detection of the memory card decreases, it is related to the performance of the computer configuration! Please switch to a higher-end computer test! Thank you ●Sandisk official has the right to repair the packaging, so if there are any packaging changes, please check with the Sandisk official Attached is a screenshot of one test achieving： FAST ENOUGH TO KEEP UP WITH THE ACTION Get extreme speeds for fast transfer, app performance, and 4K UHD.2 Ideal for your Android smartphone, action cameras or drones, this high-performance microSD card does 4K UHD video recording, Full HD video and high-resolution photos. The super-fast SanDisk Extreme PRO microSDXC memory card reads up to 170MB/s and writes up to 90MB/s. Plus, it’s A2-rated, so you can get fast application performance for an exceptional smartphone experience. SAVE TIME TRANSFERRING CONTENT Quick read speeds of up to 170MB/s* let you transfer 1000 high-resolution photos and 30 minutes of 4K video (24GB) in less than 3 minutes. WRITE SPEEDS OF UP TO 90MB/S Capture fast-action photos or shoot 4K UHD video2 with write speeds of up to 90MB/s.* The SanDisk Extreme® PRO microSDXC™ UHS-I Card lets you shoot more and faster. GREAT FOR CAPTURING 4K UHD VIDEO Ideal for recording outdoor adventures, weekend trips, or sporting events without skipping frames. With up to 400GB1, the SanDisk Extreme® PRO microSD™ UHS-I card lets you capture uninterrupted 4K UHD and Full HD video with its UHS Speed [ATTRIBUTES] - Hign-concerned Chemical: None - SD Type: microSDXC - Application: High Speed Read and Write,MOBILE PHONE,Tablet,Tachograph,Speakers,Digital Devices,UAV - Hign-concerned Chemical: None - SD Type: microSDXC - Application: High Speed Read and Write,MOBILE PHONE,Tablet,Tachograph,Speakers,Digital Devices,UAV - Application Performance Class: None - Video Speed Class: None - UHS Level: None - Class Level: C10 - Package: Yes - Type: TF / Micro SD Card - Brand Name: SanDisk - Origin: Mainland China - Certification: CE - Ultra 64G-128G property: A1 Read 140MB/s - Ultra 256G-1TB property: A1 Read 150MB/s - Nintendo Switch property(1): Read 100MB/s and write 90MB/s - Ultra property: A1 U1 C10 - Nintendo Switch property(2): U3 C10 4K - Gold card Extreme property(1): A2 Read 190MB/s and write 130MB/s - Black card Extreme pro property(1): A2 Read 200MB/s and write 140MB/s - Gold card Extreme property(2): A2 U3 C10 4K - Black card Extreme pro property(2): A2 U3 C10 4K - Gold card Extreme property(3): A2 Read 190MB/s and write 90MB/s - Black card Extreme pro property(3): A2 Read 200MB/s and write 90MB/s - White card HIGH ENDURANCE property(1): Read 100MB/s and write 40MB/s - White card HIGH ENDURANCE property(2): U3 C10 4K