Master Lock 5420EC Set Your Own Combination Portable Lock Box - Secure

In this review of the Master Lock 5420EC portable lock box, the bottom line is simple: it is a practical, weather resistant key safe best suited for homeowners, property managers, and caretakers who need a straightforward way to share keys without handing them over in person. The unit's biggest selling point is the user controlled 4 digit combination and the adjustable shackle that cinches to a wide range of door knob styles, making it easy to install and convenient for regular use while keeping keys accessible yet out of plain sight.

Key Features

• Adjustable shackle: The adjustable shackle cinches tightly to most lever, ball, biscuit, and tulip door knob styles so the box stays put during daily use.
• Set your own combination: The 4 digit combination can be set and reset by the owner, allowing thousands of personalized codes for easy recall and shared access.
• Weather protection: A vinyl coated shackle, molded bumper and weather cover protect the metal body and combination dials from outdoor elements and scratching.
• Durable construction: Metal body construction gives the box durability for indoor and outdoor use while maintaining a discreet black finish.
• Generous capacity: The internal layout holds up to six standard keys, making it useful for families or small teams who need shared entry.

Who It's For

The Master Lock 5420EC is aimed at homeowners, short term rental hosts, maintenance personnel, and real estate agents who need a simple, portable way to share keys without rekeying locks or distributing duplicates. It is especially practical where an adjustable attachment is useful and weather exposure is a factor.

Those who should look elsewhere include people requiring maximum high security tamper resistance or electronic access control, since this box relies on a mechanical 4 digit code and a physical shackle rather than electronic authentication or reinforced safe steel.

Pros & Cons

Pros

• Easy to program and reset the 4 digit combination for simple shared access.
• Adjustable shackle fits many knob styles, helping ensure a tight, stable mount.
• Weather cover, vinyl coating and molded bumper reduce corrosion and scratching for outdoor use.
• Compact internal space holds up to six keys, useful for families or small teams.

Cons

• Some users report mixed long term functionality with the combination mechanism after repeated use, so heavy daily use could reveal mechanical wear.
• Not intended as a substitute for a high security safe; it offers convenient access rather than maximum theft resistance.

Specifications

External Dimensions	7 in H x 2.875 in W x 2.06 in D
Internal Dimensions	4.188 in H x 2.375 in W x 1 in D
Shackle Length	0.75 in to 1.75 in (19 mm to 44 mm)
Shackle Width	1.406 in (35.71 mm)
Shackle Diameter	0.375 in (9.52 mm)
Key Capacity	Holds up to 6 keys

Our Verdict

The Master Lock 5420EC is a sensible, value oriented key lock box for anyone who needs easy, shared access to keys outdoors or indoors. Its adjustable shackle and customizable 4 digit combination make it flexible and user friendly, while the metal construction and weather cover add durability. It is a good buy for homeowners and property managers who prioritize convenience over maximum security.

Frequently Asked Questions

Can I change the combination?
Yes. The 4 digit combination can be set and reset by the owner to create thousands of personalized codes.

How many keys will it hold?
The internal compartment is sized to hold up to six standard keys.

Is it suitable for outdoor use?
Yes. The unit has a vinyl coated shackle, molded bumper and weather cover to protect the dials and finish from the elements.