Who doesn't know the situation- you have got a 1/4inch photoscrew and the metric allen keys you've got don't fit without damaging the screws head. For just one screw there is no need for an entire set of allen keys. The Allen Key Photo is made especilly for the 1/4 inch photo adaotion screws.
The precice measure is 3/16 inch
Find below our recommended accessories like the photosrews themselves.