1914-15 star on chain

Here is my ww1 14-15 star. Anyone have any guesses as to what the chain on it was used for??? Could have been made into necklace but is quite bulky and would sit quite low on chest. A 14-15 star is fairly common as most of you know and are often seen at military shows. What I like about mine is the EXTREMELY low regimental number. Also another question I have is does anyone know when they started using the ww1 style of regimental numbers? As my guy enlisted about a month after the war officially began. I paid $40 for the piece which is about retail for a normal star but because of the number I snatched it up. Does anyone know if the number adds much value or just a value of interest? Also wanted to share that at the beginning of the war they repetitively used the numbers multiple times (I believe there are 11 #1's and 14 of my number if I remember right). Appreciate any other comments, questions and corrections.
Thanks!
Beau