The Slam Lock variant will automatically lock every time the door is slammed shut, requiring the key to be opened again. This is for high-security cargo and high-crime areas for vans that need to be locked every single time. It gives the driver peace of mind that every single time the door is closed, it’s locked.
The Dead Lock can do both. If you turn the key to the right, the lock with be disengaged and won’t lock until set back, so it doesn’t lock every time you slam the door. This version is designed for vehicles that must stay protected but are making a lot of stops in the day, such as last-mile delivery.