I have several watches all with slotted cases which seal the back of the watch. It is nigh on impossible to remove these case covers unless you have the proper tools. I took 2 of my watches to 'watch repairers' to get the battery replaced; both stated that the battery would be replaced within the hour at a cost of £10 each, so £20 in total. I left the watches with them and when I returned an hour later both repairers told me that they were unable to open the back of the case. I left the watches in a drawer for some time and was unable to use them. I seen this tool on Amazon and thought I would give it a go. The item was ordered around 11am Friday morning and delivered around 2pm Saturday afternoon the following day! All I can say was that I opened the toolkit, got my 2 watches and within 2-3 minutes both watch cases were opened and batteries replaced. The tool is of very good quality, robust and did the job with great ease. Best fiver I have spent to be honest.