THIS IS A USED WILDEN DOUBLE DIAPHRAGM PUMP !!! I BELIVE IT TO BE POLYPROPYLENE OR TEFLON IT IS THE SAME SIZE AS A WILDEN M8 PUMP WITH A 1 3/4 INLET AND OUTLET .IT  WAS USED VARY LITTLE  AND IS IN GREAT WORKING CONDITION , YOU ALSO GET THE FLANG PLATES ANS GASKETS,BOLTS  2" HOSE NIPPLES ALL STAINLESS STEEL. LIKE NEW CONDITION, LOOK AT THE PICTURES GOOD WHAT YOU SEE IS WHAT YOU GET  ,IF YOU HAVE ANY QUESTIONS PLEASE ASK !!! MUST USE PAYPAL FOR PAYMENT !!!!