The Danco 1-1/2 in x 1-1/2 in tub trap is designed for use with drain stopper 88187 and works with mobile homes and RVs. It holds water in the U or J shaped bend to provide a liquid seal between the home and sewer gasses. Water drains through the pipe to the sewer system while maintaining the proper seal. It is crafted with a reliable and durable plastic. It has a black color that matches most existing fixtures. It also comes with a 2 in captured nut for easier installation.