It is used to connect QEV-2-8 of quick exhaust valve and pump of beat breaker.
Although it was direct attachment in genuine, maintainability was improved by arranging it in an L shape.
The seal is applied first, and the place where you can start work immediately is a feeling like a fluffy maker.
I can use it almost without problems. Because it is an amateur, I do not know the reason, but since it is sharper than 90 degrees it is a little worrisome that piping becomes oblique. Is elbow like this for some reason?