http://tinyurl.com/l4wkh8x
Earl's 991902 Blue Anodized Aluminum -4 Male to -3 Male Union Reducer
AN adapter side seals on the flare (cone) not the threads
Precision machined to exacting tolerances for trouble-free performance
Made in the USA
Should not be overtorqued to prevent damage to part
Made in the U.S.A.