18 Gauge premium grade 304 series stainless steel. Includes a removable basket strainer inside the drain which catches hair and other debris from entering your drain, allowing you to pop off the cover lift up the basket strainer and clean it out once in a while. 2" slip in drain diameter. Shower drain base not included but is required and available as model # ABDB55 in PVC or ABDB55CI in Cast Iron. In order to maximize water drainage, instillation requires that the shower floor include a slight slant towards the direction of the drain. See installation instructions for further details.