Watch fobs were commissioned by Osaka Mainichi Shimbun and were manufactured by the Japanese Mint.
Mint also manufactured table medals with the same design https://asiamedals.info/threads/japanese-mint-ww1-commemorative-table-medals.26291/
Today thee variants of the watch fobs are known: gold, silver, and silvered watch fobs.
Gold watch fob.
Size 25.5 mm.
Weight 13 g.
Watch fob obverse was designed by artist J.Iida. Reverse was designed by famous medal artist I. Sato.
Obverse
平和 - Peace
造幣局製 - Made by the Mint
reverse
世界戦役講和條約調印記念 - Commemorating the Signing of the World War Peace Treaty
大正八年六月二十八日 - June 28, 1919
Mint also manufactured table medals with the same design https://asiamedals.info/threads/japanese-mint-ww1-commemorative-table-medals.26291/
Today thee variants of the watch fobs are known: gold, silver, and silvered watch fobs.
Gold watch fob.
Size 25.5 mm.
Weight 13 g.
Watch fob obverse was designed by artist J.Iida. Reverse was designed by famous medal artist I. Sato.
Obverse
平和 - Peace
造幣局製 - Made by the Mint
reverse
世界戦役講和條約調印記念 - Commemorating the Signing of the World War Peace Treaty
大正八年六月二十八日 - June 28, 1919