Easy to install. PDF installation instructions are available.Rubber gasket included.Installed to a standard round shower drain pipe in order to accommodate for square drain attachment, or for complete relocation of drain for linear/square drain installation.Required part if purchasing a linear or square shower drain.This part will not be visible, and is installed underneath the linear or square drain plate.PVC construction provides durability and resistance during hot mop sealing process.Similar drain base made of Cast Iron also available as model # ABDB55CI