1st War? British Hat Cap Metal BADGE w/ RMEE Just Found Small Collection #4

Description

See the photos of this very nice UK hat badge.  Not sure of value nor which war.  I just found a small collection of various British badges that I must have acquired in the 1990s.  I'm listing each one separately so please peruse them.
100% original in every way.
Shipping, handling and insurance in the US is .99.