Master Lock No. 5 (laminated steel padlock)
D0 No Radio — No radio at all. It cannot phone home.
The unplug test
Nothing to unplug. A key turns a mechanical cylinder that throws dual ball-bearing locking dogs into the shackle. It works identically whether the internet exists or not, whether Master Lock exists or not, and whether the last decade happened or not — the same lock body has been sold for years with no firmware to update and no account to create.
Why this tier: A purely mechanical keyed padlock: laminated steel body, hardened boron-alloy shackle, non-rekeyable 4-pin cylinder. No battery, electronics, Bluetooth, or app of any kind. Master Lock's own grantee code (MZR) has 36 FCC filings for its radio-equipped products, including a Bluetooth-enabled lock (MZRD1000) and multiple Zigbee/Z-Wave smart locks — confirming Master Lock demonstrably files grants when a product has a radio — and no filing exists under that grantee for the Model 5, satisfying the sibling-control test for a meaningful absence.
Specifications
| Account required | none |
|---|---|
| Works offline | fully |
| Forced firmware updates | no |
| Radios | none |
| FCC ID | no intentional-radiator grant found |
| Local control | none |
| Phones home | none |
| Parts available | limited |
| Availability | in stock |
| Price band | $15-25 (seen 2026-09-03) |
| Vendor risk | 0 / 3 |
Where to buy
Open questions
- Exact current retail price varies by retailer and by keying option (keyed alike vs. keyed different); band reflects the manufacturer's own list price.
- No independent teardown was found confirming the sealed body contains no electronic component; relying on the manufacturer's own description plus the FCC absence check.
Sources
Class A is primary (manual, FCC filing, teardown). Class B is corroborated community reporting. Class C is never sufficient alone.
- A https://www.masterlock.com/products/product/5
Manufacturer product page: confirms purely mechanical keyed padlock with no electronics/Bluetooth/app; 2in laminated-steel body, 3/8in hardened boron-alloy shackle, non-rekeyable 4-pin W1 cylinder, dual ball-bearing locking, list price $21.47. — accessed 2026-09-03 - A https://fccid.io/search.php?q=master+lock
Sibling-control check: Master Lock Company LLC (grantee code MZR) holds 36 FCC filings for radio-equipped products, including a Bluetooth-enabled lock (MZRD1000) and multiple Zigbee/Z-Wave smart lock modules, establishing that Master Lock demonstrably files when it ships a radio. A separate targeted search under the same grantee for a 'Model 5' padlock returned no matching filing. — accessed 2026-09-03
History
- 2026-09-03 — First published at D0.
Last verified 2026-09-03 — 3 days ago.