Review on Amplim 64GB V90 UHS-II SD SDXC Card: Lightning Speed, 300MB/S, Secure Digital Memory Storage for Pro Photographer and Videographer by Luckie Davidson

This card is perfect for Panasonic GH5. When using All-I 4K 10bit 400Mbps mode, the card never fails. It easily fills the card every time, offering a full hour and 24 minutes of recording time. This is the only 256GB card I know of that never fails in this mode. That's about the same price as expensive brand name 128GB cards, making them incredibly affordable.