Safety air filter 26510381 for Perkins engines is designed to provide basic protection in case of a defect with the main diesel engine air filter. Providing filtration protection to remove particulates and give the best protection for your Perkins engine. Normal practice is to change the safety element every 3rd time the main filter is recommended. You can’t control the environment you’re working in, but you can keep your engine working longer by keeping the air used for combustion clean. Removing particulates prevents wear to vital components such as injectors and turbochargers.