Lockbox - Quality Realtor Lock Box - Real Estate - "The Blue Box" Attractive Blue Design - Heavy Duty - Quality Built - Created by a Real Estate Broker Hardened Steel Shackle with Vinyl Shackle Guard - Soft Padded Backing, twice as thick as most competitors. 4 Digit Numeric Combination Lock. 10,000 possible combinations for added security Extra Large Storage Compartment, permanently hinged (no more misplaced lids) - Fits more than just keys! Durable rubber protector keeps combination concealed, secure and protected from weather