These blocks can be used to quickly drill piezo disks. You can use disks with or without the cables soldered on. Place the disk in the bottom part and clamp it down with the top. If you have cables, arrange them so that they are not in the way of the clamping parts or the drill guide. Use an electric drill with a 5mm drill bit. The drill hole will guide the bit and the bottom support will protect the ceramic from cracking. The advantage of this setup is that you can drill the piezo disks very quickly and there will be minimum to no sleeves so you won't have to clean up the hole afterwards with a file etc...