M & O Backflow Testers 📍 154 Muirwood Pl, Vallejo, CA 94591 📞 (707) 648-1920 1.0 (1 reviews) Plumber Review SummaryUnprofessional. Reviews View All on Google 1.0(1 reviews)5 ★0%4 ★0%3 ★0%2 ★0%1 ★100% Dewy Aoz Unprofessional