It appears to be one of the 180-Degree Wheel Masters Tire Pressure Valve Extenders # WM8029180 which was then bent back out to accommodate the opening for that wheel. We do also have the 135-Degree Extenders # WM8029135 which may work depending on your exact application.
Kits like the Wheel Masters 4-Hose Inflation Kit # WM8001 are great to get the fill points further out towards the center of the hub and more easily accessible. view full answer...