Product Information Seat: Polymer Select a Product Part NumberMaterialSize GDB28Plated Iron2" (50mm) GDB23Plated Iron1-1/4" and 1-1/2" (32mm and 40mm) GDB3Plated Steel1/2" (15mm) GDB38Plated Iron3" (75mm) GDB33Plated Iron2-1/2" (65mm) GDB13Plated Steel3/4" and 1" (20mm and 25mm)