Individually tested and certified to ISO/EEC Class B (Bypass meter Class C ) Measurement of largest flow range, main and bypass meters in one single inline 50,80,100mm body design, both registers IP68 rated, copper/ glass, three pulse output options for each, suited for up to 50oC EEC approved interchangeable measuring element common for 50, 80 & 100mm sizes OIML R49 Class 2.