The ND-Series has long been one of Schlages best selling mechanical locks for good reason - its tough, durable, Grade 1 rated and fits a wide variety of applications. Now weve made our trusted ND-Series lock even better by making it easier to install. Weve added these enhancements because we know that a lock installed correctly the first time will last longer and perform better. And the longer the lock lasts, the lower the cost of ownership over the life of the lock. Weve also increased our **to provide 10 years of coverage. The result: greater peace of mind that every door is safe and secured with a lock built to last.