Made of Neoprene this is a replacement INLET & DISCHARGE valve assembly for Edson Double Diaphragm Pump 2500 Series, 25000 Series and the 25200 Series.
Neoprene a synthetic polymer similar to rubber, it is highly resistant to oil, heat, and weathering, ideal for pumps.
160-G-302 - Double Diaphragm Pump | Flapper Valve Part Breakdown - Data Sheet