Sales, Certification, Calibration and Repair Services for Back Flow Prevention Test Kits. backflow test kitBUFFALO BACKFLOW TEST KITS Buffalo Backflow Test Kit is a certified portable testing device made for testing all RPZ (reduced pressure zone) backflow prevention assemblies, DCVA (double check valve assemblies) and PVB valve assemblies. Home of the 6-year warranty the best in the Back Flow Industry The Buffalo Backflow Preventer Test Kit is ready to use out of the box, with a one year free NIST traceable certification, rugged foam lined carrying case, and adapters