PetBird Xpress offers over 1,000 items including Nature Cluster. Our Customer Care Representatives are standing by to help with your questions. We do stock Nature Cluster and they usually ship within 1 day. We work very hard to honor our shipping and delivery estimates! PetBird Xpress is proud to represent PLANET. We never sell unproven off-brand products. We appreciate the opportunity to serve you! Join our 12,000 satisfied commercial and residential customers.