Body molded of clear polystyrene with smooth connecting barbs for easy installation. Internal flow channel diameter is 5mm, paddle wheel shell is 25mm, overall length is 51mm. Maximum recommended pressure is 10 p.s.i.g. Minimum flow: 0.5 LPM. Maximum flow: 10 LPM. Not for use with corrosive chemicals or fluids with a temperature in excess of 64°C (150°F). Per each, 12 per case.