UPR Pro-Series™ 5/8 (17mm) Billet Check Valve - 0psi Cracking 0-100psi Operating Pressure 5044-03

Ordered with my new catch can, was pre-installed on the line making for an amazingly easy install

Just put it on last week with the dual can kit. Not sure how I can tell if it'll do anything different I just went with everybody's recommendation.

Works great on my s280 Fiesta ST PCV hose.

UPR Products is a top-tier, high-quality store with excellent components. While working on a custom catch can setup for my Jeep build, I ran into some compatibility issues and, without much expectation, reached out to their team. I was surprised to find out their customer service and technical support are incredibly quick to respond, helping me sort through the technical details of my application right away.
When it came to sorting out a return, they were very helpful. Even though I was technically outside of the standard return window and didn't have the original retail box, they authorized an RMA exception for the uninstalled CSS valve so I could get it swapped out. They definitely stick strictly to their policies—they only accepted the completely unused valve and not the check valve that had already been briefly installed before I switched directions, which is fair enough for performance parts.
Overall, their response times are incredibly fast, their products are great quality, and their team is helpful throughout the process. I highly appreciate a company that backs up their high-end parts with solid, reliable communication.

Easy enough to do at home. I noticed less boost lag. Really worth upgrading.