A combination lock is a type of security lock which can only be opened by entering the correct numerical combination. Other synonyms for this type of lock include number lock, code lock, combination padlock, dial lock, and mechanical lock. Many people also refer to this type of lock as a locker lock as it is often used to secure lockers in schools, gyms, and workplaces. Combination locks are popular due to their simplicity, reliability, and convenience. They are commonly used to secure property such as gates, toolboxes, safes, and bicycle locks. Combination locks can be made using a variety of materials, including brass, steel, and aluminum, and can be customized to fit different applications.