With the introduction of MIDI 2.0, the USB Implementers Forum’s USB MIDI 2.0 working group, headed by members of the MIDI Manufacturers Association (MMA) and the Association of Musical Electronics Industry (AMEI), have updated the USB Class Definition for MIDI Devices.
A TRRS type audio jack have four conductors and are most popular with smartphones and tablets. The sequence of TRRS type audio jack is Tip-Ring-Ring-Sleeve and it includes both stereo and microphone functionality.
CFexpress™ memory cards come in 3 different formats: Type-A, Type-B & Type-C. CFexpress™ Type-B is currently the standard format, utilizing the same form factor as XQD (38.5mm x 29.8mm x 3.8mm) although the internal connections are different. By having it be the same physical size as XQD, CFexpress™ Type-B cards can be used in the same hosts as XQD cards (Note: Not all XQD hosts will support CFexpress™ memory cards. Hosts that can support CFexpress™ require a firmware update, which is provided by the manufacturer) It is important to note though that CFexpress™ cards are not backwards compatible with either CompactFlash or CFast 2.0 hosts.