This straight adapter combines an AN6 37-degree male flare with a 1/8*28 BSP thread. The 1/8*28 BSP port is a small fitting size that shows up on gauges, pressure switches, senders and older British-pattern castings, and this adapter lets you feed such a port from a standard -6 AN braided line. Note the mismatch in scale: the -6 AN side is generous relative to the small BSP thread, so the BSP end will always be the restriction. BSP is a 55-degree thread form and is not interchangeable with NPT, so do not attempt to run an NPT fitting into a BSP port or the seal and the threads will both suffer.