The M39077 brake master cylinder withe the bore diameter 1-1/8" (equal to 28.58mm) is made by cast iron material. It is dual circuit type with two outlet port, and the size of the two outlet ports in left side is 1/2-20" of the forward, and 9/16-18" of the rearward. And the reference numbers of this cylinder are 18001007, 18002455, 18005250, 18009462, 2621565 and ect...
