I'm not sure why this item is so highly rated here on Amazon (4.5 stars); I find most reviews quite accurate but this item is very poorly made with large tolerances so the tips wobble, the tips themselves have an odd shape that will fit most cases poorly and unfinished sharp edges that will badly scratch the case if they slip. I have purchased other screw-back case openers (a jaxa type for $19 (see my review), a suction type for $12) and they are vastly superior, though more costly.  I guess if you are very careful with this tool and you will very RARLY use it (e.g., only to change a battery once every couple of years), it might be worth the money. If you collect and/or repair watches, I say do not buy.