These fittings are designed to fit mechanical fuel pumps used on Lycoming engines. These fittings feature 3/8" AN flare outlets for connection to aircraft hoses, and are available in straight, 45° and 90° angle versions.
Note: These fittings are not FAA approved.
Addressing the previous reviewer: This is not common but can happen. The parts involved are pipe thread so each have a taper to them. This could possibly fix itself with a different AN822 but most likely it has to do with the KB 90 T being tapped a little deeper than normal. Easy way to fix this would be to simply sand down the length of the AN822.
Use extreme caution with this part. Threading an AN822 fitting into the 1/8 NPT hole will result in the fitting partially blocking the fuel flow through the part.
P/N# for the O-Ring on the fitting is MS29513-111.