A Deadbolt that locks by key on the outside and a turn piece on the inside of the door.
A Deadbolt that locks by key on the outside and inside of the door. **Double Cylinder locks on doors used for exiting a building or a home are a life safety hazard in times of emergency and are not recommended**
A one sided deadbolt locks a door from the inside. These are commonly used on patio doors.
A deadbolt thrown or retracted by key outside. Inside turn unit will retract bolt only. Bolt automatically deadlocks when fully thrown.