SmartKey, #3 Bright Brass Finish, Smart Key Control Single Cylinder Deadbolt, Landlord/Tennant Double Cylinder Exterior Features Smart Key Re-Keying Functions On Both Of These Cylinders, The Landlord Master Keyway & The Tenant Keyway, With Just A Flip Of A Sliding Cover The Master Keyway Is Exposed, Keep All The Property Management Operational Control, But With A Higher Level Of Security For Tenants & On Site Property Maintenance Employees At The Same Time.