TWO-CONTACT VISUAL AND ELECTRICAL LEVELS code 10.720

The levels belonging to this series have the same characteristic as those belonging to the code 10.700 and 10.710; besides having the minimum level electrical switch, they are also equipped with the maximum level switch

N.O. - Contacts are normally open - they close when the minimum or maximum levels are reached.
N.C. - Contacts are normally closed - they open when the minimum or maximum levels are reached.
S.C. - Exchange contact allow to have a N.O. contact (at closing) and a N.C. one (at opening)