Feature1
  The outer surface of Riser has furrows and hoops, so height can be controlled instantly at 2" intervals from 26" to 37 13/16".

Feature2
  The round body promotes durability to endure deformation and damage caused by earth pressure. 

Feature3
  As the upper and lower parts of the body can rotate 360° separately, the position of drainage pipes and the angle of surface can be fixed correctly. 

Feature4
  The streamlined upper part of catch basin promotes flow of rain water and prevents leaves from being piled up. 

Feature5
  Uneven parts of edges of the upper part prevent the brims from being separated to outside of the body. 

Patent application: No. 10-0662666