The results… the swivel will turn easily and will not leak. The machined surfaces of all swivel castings have porosity (tiny holes). These holes cause wear on the O-rings when the swivel rotates. A sealant is required to fill the holes to attempt to stop leaks. The SLEEVE eliminates both problems.

M Carder Performance Advantages

Brass male end will not gall in nozzle castings
Dual O-rings seal with all fuels
Machined Brass sleeve gives smooth seal surface – NO LEAKS
Internal nylon retainer cord secures firmly, but allows for free rotation