Master Lock 6400EURLJENT Professional Bluetooth Smart Padlock [Bluetooth Compatible with Smartphones] [Long Shackle]…
Best for
Best hanging shackle
Amazon rating
Amazon aggregate, one input among many in the Verdict Score
Current price
$209.95
Updated May 18, 2026 · 1 min read
![Master Lock 6400EURLJENT Professional Bluetooth Smart Padlock [Bluetooth Compatible with Smartphones] [Long Shackle]…](/_next/image?url=%2Fimages%2Fproducts%2F1d63aa1cf330615a.jpg&w=3840&q=75)
Sources behind this verdict
1 reviewer weighted by source trust
The consensus
What reviewers found
Synthesized across the trust-weighted source mix below.
Across the reviewers we read, the Master Lock 6400 ProSeries Bluetooth padlock occupies a different niche than the rest of this list — it's a smart padlock for securing gates, containers, and construction sites rather than a key safe. cnet.com highlights the ability to grant temporary or timed access via the Vault app and track unlock history, and homedepot.com verified-purchase reviewers describe three months of trouble-free use with comments like 'expensive, but worth it.' The evidence base is thinner than for the consumer-grade Master Lock boxes. Only 19 Amazon ratings are present (albeit at 4.6 stars), and there are no Reddit threads in the supplied signals to corroborate long-term durability.
What reviewers liked
- cnet.com cites time-bound access codes and unlock-history tracking via the Vault app
- Long-shackle, weatherproof design suited to fences, containers, and construction sites
- homedepot.com long-term reviewer reports 3 months of reliable service
- 4.6 Amazon average (small sample) is the highest in this candidate pool
Where it falls short
- Only 19 Amazon reviews — limited volume to validate long-term reliability
- At ~$210, significantly more expensive than competing smart padlocks
- No Reddit or specialist-community signals present to corroborate
- Not a key safe — buyers looking to store keys behind it should pick a different product
Across the reviewers we read, the Master Lock 6400 ProSeries Bluetooth padlock occupies a different niche than the rest of this list — it's a smart padlock for securing gates, containers, and construction sites rather than a key safe. cnet.com highlights the ability to grant temporary or timed access via the Vault app and track unlock history, and homedepot.com verified-purchase reviewers describe three months of trouble-free use with comments like 'expensive, but worth it.'
The evidence base is thinner than for the consumer-grade Master Lock boxes. Only 19 Amazon ratings are present (albeit at 4.6 stars), and there are no Reddit threads in the supplied signals to corroborate long-term durability. A YouTube comparison with the indoor 4400D notes that the long-shackle outdoor variant feels like 'premium hardware' but carries premium pricing to match.
The synthesis: for commercial or outdoor scenarios where the lock itself secures the asset — rather than guarding a spare key — this is the most credible smart-padlock option in the candidate pool. Consumer key-safe shoppers should look elsewhere.
- PROFESSIONAL APPLICATION Vault Enterprise Incl
- heavy duty outdoor padlock for fences, containers, toolbox, construction site access, industrial site (water treatment, telecom antenna) and more
- Master Lock Vault Enterprise
- use your smartphone to open your padlock with the Master Lock Vault Enterprise app or the manual combination entry (available for Android and iOs + web interface)
- Flexible Asset Management
- administrators can give permanent or temporary access to employees, create groups for specific locks or key safes or create a real customized access-system
- High Security Padlock
- Wide Zinc lock body with complete rubber bumper and 256 bit military grade encryption; boron alloy shackle offering maximum resistance to cutting and sawing
- Weather Resistance
- Weather cover provides enhanced weather resistance against snow, rain and temperature extremes ; -40 C to +70 C.SPECIFICATIONS: padlock (H x W x D) 16,4 x 6,2 x 4,3 cm ; shackle (A x B x C) 6 x 2,3 x 0,9 cm
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