A security feature is a device or system designed to protect people and property from harm. Peephole, with 8 letters, is a small hole in a door that allows the person inside to see who is outside without opening the door. ALARM, with 5 letters, is an electronic device that makes a loud noise when triggered by an intruder. SEAL, with 4 letters, is a device used to secure a door or window to prevent unauthorized entry. SENSOR, with 6 letters, is an electronic device that detects movement or changes in the environment. Onewayglass, with 11 letters, is a type of glass that is transparent from one side but reflective from the other, making it difficult to see through from the outside.