With Expertise Built In , the OTR AD-IS / IP Purge Valve Assembly Kit is the perfect solution for restoring your brake dryer’s efficient operation by properly regulating the flow of air or gases in the system. This highly reliable assembly kit is specifically designed for AD-IS / IP air dryers, being manufactured using state of the art technology for guaranteed reliability. OTR understands what it takes to repair and maintain Class 6-8 trucks, so they deliver solutions, making your job easier and more efficient. OTR warranties are comparable to or better than OE and top brands. All heavy duty truck parts offer the same form, function, and fit as the OE replacement parts. FleetPride is your First Click in Heavy Duty .