A postal horn (post horn). Depicted as a coiled, valveless, brass horn, like a bugle or trumpet, with two red tassels. Sometimes used to mark announcements as well as for various content concerning brass instruments, music, or mail.
In the 18–19th centuries, post horns signaled the arrival of and cleared the way for mail coaches, like a modern-day siren. Used today as a symbol on postboxes (mailboxes) and by many European postal services, as seen featured in ? European Post Office.
Postal Horn was approved as part of Unicode 6.0 in 2010 and added to Emoji 1.0 in 2015.
U+1F4EF
? Postal horn