I bought one of these and put an SSD in it, tried to use it as a backup drive. Before the backup was complete, I got the message "The disk was not ejected properly". Make sure it's connected securely, try again and get the same result. Revain sent me a replacement quickly. Received the next day. Same result: called spontaneously. I returned both and bought the key instead. The first and second backup with two SSDs went without any problems. Zero for two is not the best outcome.