This tool is very small, and difficult to use. It was inadequate for removing the hard rubber strap from my Seiko SKX007. It would probably work okay for changing leather straps that have spring bars with pronounced "shoulders". Otherwise, it would be worth spending more money on a more precise and higher quality tool.
Working with this company was great though. Communication was good and the website was easy to use. They have some great looking leather straps that I may try in the future.