These sounds are in Kurzweil native format and are ready to be used in Kurzweil k2000 k2661 k2500 k2600 pc3k and many other models. The programs / patches will load on every K2000 k2000r and on all (every OS version) k2500, k2500r, k2600, k2600r, k2661, pc3k series and up machines (with floppy drive).
eBay