Previously, I had bought a Schaller lock for an Epiphone ES339.  The screw that came with the Schaller lock was too skinny and couldn't get a bite into the wood.  And I could not use the original Epiphone screw because the head of the screw would not fit into the Schaller lock.  I then installed these Dunlop strap locks on the same guitar with good results.  I also installed these Dunlops on an Epiphone Les Paul ES Pro and an Epiphone Viola Bass guitar.  For the Epiphone Les Paul ES Pro and the ES339, I did not need to do any drilling and the new screws got a good bite into the wood.  But, on my Epiphone Viola Bass...when I was installing the provided screw near the neck...the screw hit something solid which might have been the truss rod.  I had to cut-off about 1/3 of an inch on the screw to make it fit.  Again, I could not use the original Epiphone screw because it just doesn't fit the Dunlop lock.  As others have mentioned, the Dunlop locks "stick out" about 1 1/8 inch from the guitar when the strap is attached.  It looks a little weird, but I'm sure I'll used to it.  I plan to get a couple more of these same locks to put on my other guitars.