AN6 is the most common size for EFI fuel feeds, so this is the size most builders reach for when a fuel pressure sender or gauge needs a home. The body carries an AN6 male flare, an AN6 female swivel and a 1/8″ NPT female branch, so it fits inline anywhere an AN6 union would go. Because the port sits in the flow path rather than on a dead-end tee, readings track the line pressure the engine actually sees. The 37-degree flare seats mate with any AN6 hose end. Suitable for petrol, oil, coolant and air systems. Wind the sender in against thread sealant only, never against tape wrapped over the leading thread.