There are more expensive tools out there that are way better.  But, if you're only going to change a couple of bracelets for watches every now and again this tool is inexpensive and will work.  Be warned - you can scratch your bracelet or the watch itself with the metal screw head on the one side of the tool.  I never use it to adjust the width of the platform so I have taped it over to avoid nasty deep scratches from it.