Holman BLACKSTONE BLACK COMBO (1 pc) Security Lock Model 84430Holman BLACKSTONE BLACK COMBO (1 pc) Security Lock Model 84430 The DAKEN Locks BLACKSTONE system offers automatic and robust security tailored for the demanding needs of couriers and fleet operations. This innovative lock ensures cargo is secured instantly with every door closure, eliminating the need for keys in routine operations. The COMBO version allows for a manual override to temporarily override the auto lock mechanism. Characterized by an