2 x 1 1/2" PVC Threaded Reducing Bush

these fittings have different sized threaded ends - the larger end is designed to thread into a female BSP thread, and the smaller end is designed to take a male BSP thread. 2" measures 60.3mm, and 1 1/2" measures 48.3mm. The larger size name of the fitting denotes the size of female BSP it threads into, and the smaller size name denotes the size of male BSP thread it takes. Inch size names do not measure the same as an inch on a ruler. 2