Rank #4 in Best Key Safe 2026: 10 Ranked, and the Numbers That Don't Add Up
Master Lock Portable Key Safe with Shackle, Medium
Price and rating as shown on Amazon when we collected them. Both change.
The Master Lock 5400EURD (the spec panel also lists 5400D as the model number) is the odd one out in this list: it is not a box you screw to a wall. It is a metal lock box with a shackle, sold at £29.40, rated 4.3 out of 5 from 1,626 ratings, and ranked first in Amazon's Key Cabinets category and 41st in DIY & Tools. It sits at number 4 here.
Where the other listings contradict themselves on size, this one largely holds together — and that is the finding. The title says 90 x 157 x 40 mm; the fourth bullet says 15.7 cm x 9 cm x 4 cm. Same box, same numbers. But that same bullet calls the cavity "large" and then measures it: 7.4 cm x 6.8 cm x 3 cm, or roughly 151 cm³ of interior against 565 cm³ of exterior. The copy says the four-digit dial offers "thousands" of combinations; four digits actually give 10,000, so here the marketing understates rather than inflates. The rating breakdown the page shows (67 five-star, 16 four-star, 5 three-star, 4 two-star, 8 one-star) adds to exactly 100, which puts 12 of it at one or two stars. Everything on this page comes from the Amazon listing itself, not from any test of our own.
How those 1,626 ratings break down
An average hides its own shape. This is the spread behind the 4.3 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £29.40 |
|---|---|
| Rating | 4.3 out of 5 from 1,626 ratings |
| Model | Master Lock 5400EURD (model number listed as 5400D) |
| Exterior dimensions (H x W x D) | 15.7 cm x 9 cm x 4 cm, shown in the title as 90 x 157 x 40 mm |
| Interior dimensions (H x W x D) | 7.4 cm x 6.8 cm x 3 cm |
| Lock type | Mechanical code lock, resettable four-digit combination |
| Special features | Anti-Corrosion, Portable, Resettable, Weather Resistant |
| Best Sellers Rank | 1 in Key Cabinets (DIY & Tools), 41 in DIY & Tools (as listed) |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“As this lock is like a massive padlock, way more versatile than a key safe that's screwed to the wall.Locking is via a combination lock, that you can easily set to your desired combination, and a little black lever.There's enough room for a few spare keys inside and the shackle is big enough to fit around railings, thinner metal poles or even door levers, I guess.With a little plastic sliding shutter, the combination is shielded from the elements. The build quality is brilliant. The shackle is thick and plastic coated, so secure from both thief and the weather and body feels really solid too.Definitely recommend if you're looking for a more portable version of a key safe, than a wall mounted key safe.”
Verified purchase“This is great. Didn't know such a thing existed until I saw one attached to some railings the other day. I'm paranoid about forgetting my house keys and getting locked out of my home. Now I have one of these in my gas meter cupboard I feel really confident that if I lost my keys or was away and needed someone else to get in I could deal with it without any problem. Peace of mind - great!”
What it is up against
The rivals it was ranked against in Best Key Safe 2026: 10 Ranked, and the Numbers That Don't Add Up.
Questions people ask
How many combinations does the Master Lock 5400EURD allow?
It uses a resettable four-digit combination dial. The listing calls this "thousands of personalized combination code options"; four digits give 10,000 possible codes.
How much fits inside the Master Lock 5400EURD?
The listing gives interior dimensions of 7.4 cm x 6.8 cm x 3 cm (H x W x D), about 151 cm³. The bullet that gives those figures also calls it a "large internal cavity" for multiple keys.
Does the Master Lock 5400EURD need to be screwed to a wall?
No fixings are listed. It is described as a portable lock box with a shackle, designed to fit over a door knob, and the reviews mention it around railings, a hand rail and inside a gas meter cupboard.
Can the Master Lock 5400EURD be used outside?
The listing says indoor and outdoor use, with a shutter door to protect the combination dials from weather, and lists weather resistant and anti-corrosion among its features. No water resistance rating is given.
What warranty comes with the Master Lock 5400EURD?
The listing states a limited lifetime warranty against mechanical failure.
How is the Master Lock 5400EURD rated?
4.3 out of 5 from 1,626 ratings. The breakdown on the page (67 five-star, 16 four-star, 5 three-star, 4 two-star, 8 one-star) adds to 100, so 12 of it sits at one or two stars.
Comments
Reader comments are not checked against the manufacturer's claims above.
No comments yet
Be the first to add something we missed — a price change, a spec that turned out wrong, or how one of these held up.
Leave a comment
No account needed. Own one of these? Tell other readers how it actually performed.