This is a Hi-Viz Sight known as the Litewave, model SF2015.
HIVIZ(R) LiteWave(R) Front Sight for Springfield Armory 1911 pistols. Fits all production models" including Range Officer" but does not fit the GI and Mil Spec models. Includes Green" Red and White replaceable LitePipes.
Features:
Interchangeable Litepipe front sight
Includes green red and white LitePipes;.090 diameter