15 basic rock riff kits. Each kits is basically a hook part which you can then break down your own way into a verse or different sections. Everything is 80 bpm and in E minor so all kits work together, which is something that makes the set quite worthwhile. Works well for inspiration or starting a track and to get a groove going. I prefer to use a variation and not only mix the loops in the kits but also mix genres to give you a hybrid sound.