These are for Gibson guitars; to put them on my Epiphone I had to adapt them. You must enlarge the hole at 3mm (pre-drill at 2.5mm, tap at 3mm, if you don't have the tools and the know-how, don't try).
Then file the lttle studs on the sides, or the saddle won't settle down at the right depth in the bridge. That's a little tedious, but brass is easy to work with files.
Once they are in, the difference in brilliance and attack is obvious, I didn't recognize the tone of my SG at first. You must also file a narrow slot where the string touches the saddle, or the string will break after many bends, because it rests on a sharp angle.
Aside from these delicates chores, the saddles are very good in tone. I wish Epiphone would make brass saddles that are compatible with Epiphone bridges, so you could simply drop them in to replace the so-so zinc saddles.