I own a first generation Microsoft Surface Pro 128, and it has been a good machine but I was really finding it challenging working within the constraint of 128GB of storage space. I had a 64GB Class 10 SDXC card, which worked well but was not going to fit the VMWare virtual machine I wanted to run off the SD storage. The Virtual Machine increases in size with regular use, and the operating system I was running is recommended for at least 40GB of max storage to operate properly.  Combined with the files I needed to store, and 64GB memory chip was no longer sufficient.The SanDisk Ultra 128GB MicroSDXC Class 10 Memory Card was able to handle that with ease, however I have found that the virtual machine ran noticeably faster off the 64GB chip than this one. I've actually ordered a second of these to see if I might have just received a flawed chip. If the replacement chip offers improvement I will revise this review. It provides its main selling point, more storage at a relatively low cost, so far has run reliably in my tablet computer.If storage space is a significant issue for your device and the memory can make use of 128GB SDXC, then I would recommend product.