Transit Slide LockTransit Slide Locks are highly recommended from a safety point of view. They help prevent your Engel fridge freezer from shifting around in a vehicle or boat. Securely attach your transit slide lock to the vehicle and then simply slide your Engel into position and it locks down automatically. To remove, just push the clip to release. It's that easy! The Slide Locks work with all Engel Transit Bags. Each Transit slide lock comes with the plastic base