The HPDS is the heavy duty option on these AR pumps used to replace other versions of diaphragms including AR550080 Gomma & AR550081 Blueflex which are now discontinued.
Annovi Reverberi HPDS diaphragm suit the following AR pump used by Croplands
AR70, 115, 125, 135, 145, 160, 185, 250, 280, 370, 500
20 Bar Max
Price is for X1 Diaphragm only!