This is the new Ireland football centenary shirt 2021, a special edition kit for the Irish national team made by kit partners Umbro. The Ireland 100th anniversary blue jersey was worn by the national side in their 4-0 friendly win over Qatar on October 12, 2021, a fixture the Irish won 4-0 thanks to a hat trick from Callum Robinson (Shane Duffy scored the other goal here)
The jersey is predominantly blue and the kit was completed by white shorts and predominantly blue socks. The back of the shirt has 1921 written on the reverse, as can be seen in the pics below.