MAC address vendor

3C:40:15 MAC Prefix — 12mm Health Technology (Hainan) Co., Ltd.; Device Unknown

Primary prefix
3C:40:15
Block
MA-L

Summary

// what this is
12mm Health Technology is registered to MAC prefix 3C:40:15 in the IEEE OUI database. When a device's MAC address begins with 3C:40:15, that block was registered by 12mm Health Technology — the OUI identifies the maker of the network hardware, which is not always the brand on the device.
// analyst note
An exact prefix match identifies the IEEE registry assignment, not a specific device or product. The 24-bit prefix leaves 24 suffix bits, or 16,777,216 possible values; this is not an observed device or shipment count. For 3C:40:15, the first-octet Group and Local bits are both zero and are fixed for an exact prefix match.
[ 01 ] — Context

About this vendor.

Updated  ·  Confidence: High  ·  2 sources  ·  How this page is checked

A MAC address beginning 3C:40:15 matches an IEEE MA-L assignment to 12mm Health Technology (Hainan) Co., Ltd.; the supplied records do not identify a device type or product using it. That match establishes the registered assignment only, not the device’s maker, current owner, operating system, location, or safety. The IEEE record gives China as the country associated with the registration.

This is a 24-bit prefix, leaving 24 bits for suffix values: 16,777,216 possible values. These are mathematical possibilities, not a count of devices, addresses in use, or shipments. The prefix’s first octet, 3C, has Group and Local bits both set to zero. For an exact literal prefix match, those bits are fixed; changing either bit produces a different prefix.

RFC 7042 describes 48-bit MAC identifiers as an initial assigned prefix followed by additional bits, and explains the Group and Local bits. A captured address matching this prefix supports an assignment lookup, but does not establish a particular device or product. The supplied IEEE CSV records contain no assignment date.

Device type
Unknown from supplied evidence.
IEEE registry
MA-L; one assigned prefix, 3C:40:15.
Country
China, as stated in the IEEE registration record.
Prefix interpretation
24-bit match, 24 suffix bits, Group bit 0 and Local bit 0.
Company
12mm Health Technology (Hainan) Co., Ltd. [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv
Registry
MA-L [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv
Prefix
3C:40:15 [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv
Country
China [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv
Device type
Unknown [Unknown] — https://standards-oui.ieee.org/oui/oui.csv
[ 02 ] — OUI prefixes

Assignments by IEEE.

1
// registered prefixes1
  1. 3C:40:15MA-L
[ 03 ] — Related

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