Plastic HDPE Flange adaptor and large tolerance flange adaptor: 1)Non-toxic: no heavy metal additives 2)Corrosion Resistant: resist chemical matters, electron chemical corrosion or rusting 3)Lower Installation Costs: light weight and ease of installation 4)Smooth interior walls: lower friction and higher volume than metal pipes 5)Long Life: more than 50 years under normal conditions 6)Recyclable:recycled and Envir...