This USB micro B "JIG" Dummy Plug is a small, handy device for those interested in debugging their smartphones or other devices that use the ID pin #4 for a special signal. This plug has a 300K resistor from the ID pin to ground, which can be used to resuscitate Samsung S4, S5, S6 and possibly others by putting into an emergency repair mode.

It's also useful for other devices where you may have to trick it into OTG modes. The other pins are not connected to, just the ID and Ground pins!