Tray CPUs, or desktop processors, are often cheaper than traditional retail and computer manufacturers, as they are often sold in large quantities at a volume discount. The main advantage of a boxed processor is the extended manufacturer’s warranty, which often lasts only two years. However, PC processors are designed for an average lifespan of at least 10 years and their failure rate is low. Some boxed CPUs come with a cooler included, allowing users to purchase more expensive items without having to purchase separately. However the lower purchase cost generally outweighs the disadvantages of tray processors.