The Grainger Approved Diaphragm Pump Flange Kit is designed to work with Wilden diaphragm pumps. It includes 4 flanges, 8 gaskets, and 16 bolts and nuts to allow you to install the pump. The flanges are made of polypropylene for chemical resistance. The gaskets are Buna-N for compatibility with water-based fluids. The bolts are zinc plated steel and the nuts are zinc plated steel nylon insert locknuts. This kit will let you install a 1/2", 3/4", or 1" Wilden diaphragm pump. It is ideal for water transfer applications.