... for liquid, White for air, simple instruction Level meter is made from colorful glass pipeline, safty cover, needle valve ... Warm keeping typeWarm keeping type allowed steam pressure less than 0.6MPa, connection: thread, M12x1 outerSafty steel ball self-locking ... pressure: greater than 0.3MPaMeter matirial: I for carbon steel, II for 1Cr18Ni9Ti, 304 ...