Normally, a freestanding stone resin bathtub will be installed with pop up drain and a popular drain set is like below image shows
Bronze body with Ni or Chrome plated surface, the cover of drain head can be changed to acrylic solid surface(same material as tub body) like the below image shows, which will make tubs looks like a whole stone piece


Why it is anti odor? Due to a fully filled water storage container is equipped which can block odor go through drain pipe


