The 45 degree fitting uses standard 1/8 inch NPT fittings on both ends.
This is rated for up to 3,000 psi working pressures (usable for all paintball applications).
This fitting is usefull when you need to angle a gas line away from the grip of your paintball gun.
Make sure the hose you are connecting to uses this standard fitting. A few guns use custom or metric fittings.