Wilden® Equalizer® Surge Dampener - Integrated SD Series (ISD) feature a design that integrates the dampener directly into the manifold of Wilden’s 13 mm (1/2") and 25 mm (1") P100 and P200 Pro-Flo Series bolted plastic pumps. The new ISD Series dampeners have been engineered to help extend the life and reduce noise while having the capability to easily screw onto the top of your pump without any additional hardware or piping changes.