This is a pack that has four different songs. Each song features distorted or crunchy guitar, and powerful groove on bass and drums.
Track already exist as a single files on my audiojungle portfolio. Buying a whole pack, you could save some money 
Here is a list of tracks :
1 .http://audiojungle.net/item/winner/97821 Winner (1:50 )
2. http://audiojungle.net/item/rock-in-da-house/111774 Rock In Da House ( 1:15 )
3. http://audiojungle.net/item/hard-as-a-rock/104432 Hard As A rock ( 1:04 )
4. http://audiojungle.net/item/rusty-metal/110957 Rusty Metal ( 1:33 )