A:AnswerIf you shoot JPG images, these speed things don't matter much. If you shoot video in 720 or 1080p, you shouldn't have any issues with this card. U1 is slower, and U3 is fastest.
A:AnswerHi Chaotikbeauty, we can't guarantee functionality of the card with third party products. We recommend consulting the manual of your camera for the recommended cards you can use with it. Thanks_Mitch
A:AnswerHi, You may have to check if your camera supports Class 10 UHS-I 128GB SDXC memory cards since we do not have available specification about your unit. Best regards, Zander
A:Answerhi Rich, based on the specifications of the HDR-CX440, cards with a capacity up to 64 GB have been confirmed to operate properly with this product. Dave