For best results, replaceevery 4-6 months. 🔹Perfect Compatibility – Designed to fitShark Stratos NZ860UK, NZ860UKT, AZ913UK, AZ913UKT, IZ400UK, IZ400UKT, IZ420UKT, HZ3000UKT, HZ3000, HZ3002, AZ3000, AZ3002, IZ562H, IZ862H, ZD550 vacuum cleaners.