Wrong size hex wrench in box, so be careful or else you could round off the hex wrench or the inside of the grub screws. You might need to get a separate set of wrenches. I suspect the wrench in the box was metric, because my own wrench that ended up fitting was SAE in inch fractions ( might have been 1/64", but don't quote me on that). Some of the saddle heigh adjustment screws were a little tight at first, but loosened up by turning them back and forth a little bit with the correct size wrench, probably just tight machining tolerances. I might run some sandpaper or a file in the saddle grooves to address a little bit of string buzz that seems to be coming from the bridge, the saddles are all identical so my thicker strings might benefit from adjusting those slot width or groove angle a little bit.I bought these to replace some slightly grooved saddles on an Ibanez YY10 that had the bent steel type saddles (which comes with a Wilkinson bridge... I kept the original bridge, screws and springs but just replaced the saddles with these).Anyways, my situation is probably not typical since I didn't drop in the whole bridge, but just wanted to share my experience. I didn't realize at first that this doesn't appear to be the actual Wilkinson brand (just Wilkinson style), but since the Wilkinson branded saddles themselves are like $100 for a set, I figured I could make due with these, expecting that some adjustments would be beneficial to get things just right. And every guitar is probably different so my experience might not be typical.Anyways, good luck to everyone else with their projects !