TLDR Review: Master Lock 5423D Lock Box
Verdict
While the Master Lock 5423D offers some promising features like durability, ease of use, and improved security, its frequent functional failures and security concerns cannot be overlooked. Many users have reported issues with it failing to open, even with the correct code, which undermines its key function. Unless resolved, these issues make the lock box a risky buy for those who prioritize security and reliability in their key storage solution. Consider these factors carefully before purchasing.
- Top pro:
- Extremely durable and reliable, with one unit lasting over four years in outdoor settings.
- Top con:
- The lock box often fails to open, even with the correct code, indicating a possible design flaw.
Pros
- •Extremely durable and reliable, with one unit lasting over four years in outdoor settings.
- •Easy to use, especially in low light conditions due to the mechanical keypad design.
- •Offers a high degree of customization with twelve buttons, allowing multiple code combinations.
- •Features a hanging hook for storing keys conveniently.
- •Suitable for emergency home access, providing security for family and emergency workers.
- •Improved security with the ability to be screwed onto a wall.
- •Reduces temptation for thieves as it is more secure and difficult to pry open.
- •Sturdy and strong, ideal for outdoor use.
Cons
- •The lock box often fails to open, even with the correct code, indicating a possible design flaw.
- •The plastic turnkey pins are fragile, and the tool is considered flimsy.
- •The design allows any order of the same numbers to unlock it, compromising security.
- •The code mechanism’s inability to use each number more than once limits the combinations available.
- •Lacks masonry anchoring points for brick mounting; only timber screws are provided.
- •Issues with performance in cold weather suggest potential problems over time.
- •Users report difficulty removing the lock box due to internal fastening bolts.
- •The lock often sticks, leading to unreliable operation.
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How we researched this
About this review: it summarizes the professional reviews and customer ratings ShopSavvy collected for this product, alongside prices from 4 retailers in ShopSavvy's price data, most recently seen May 28, 2026.
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