1.Non-toxic health 2.Easy installation 3.Superior physical properties 4.Cheap price 5. At least 50 years of life Specifications: Diameters : ( 20,25) (32,20) (32,25) (40,20) (40,20) (50,20) (50,25) (50,32) (50,40) (63,20) (63,25) (63,32) (63,40) (63,50) (75,32 ) (75,40) ( 75,50) (75,63) (90,40) (90,40) (90,50) (90,63) (90,75) (110,50) (110,63) (110,75) (110,90) Feature: 1. Save raw material, low ...