Euro cylinders are commonly found in the majority of double glazed doors, french doors, and patio doors. Their main purpose is to ensure the security of the door's multi-point locking system.
The term "Lock and Key" is commonly used to describe a security system that relies on locks and keys. This system is typically used to secure doors, cabinets, safes, and other physical objects. Lock and Key systems are specifically designed to control access and ensure security by necessitating the use of a specific key to unlock and gain entry to the protected area or object.