A -08 AN Y-block sits in the middle of the range and is a common choice where a single pump or cooler feed has to serve two destinations without dropping line size. All three ports are -08 AN. Fuel systems use it to split a feed across twin rails or to combine two returns into a single line back to the tank; oil and transmission cooler circuits use it for branch takeoffs. The one-piece billet construction avoids joints that can loosen under engine vibration. Mate it with -08 hose ends or -08 male flare adapters and tighten against the 37° flare seat, which does the sealing on its own. Where the Y carries unsupported hose weight, clamp the adjoining hose to keep load off the fitting.