Brass Closet Flange is For mounting slots for proper fit and alignment of closet bolts to the toilet.
C37700, H58-3, Lead-free brass
A typical closet flange is composed of an ABS or PVC hub with a round steel mounting flange attached to the top. Other styles are made from copper, brass, stainless steel, or pure plastic. A wax ring is used to seal the gap between the flange and the bottom of the toilet. In plumbing, a closet flange (also known as a toilet flange) is a pipe fitting (specifically, a type of flange) that both mounts a toilet to the floor and connects the toilet drain to a drain pipe.