... heating elements, one is M1700 type, which ensure max. furnace temperature 1650C ... ; another is M1800 type, which ensure max. furnace temperature ... you place order, please choose suitable type according to your furnace working temperature. ... furnace temperature 1700.C) Standard sizes:M1700 type (d/c): dia3/6, dia4/9, ... dia6/12, dia9/18, dia12/24M1800 type (d/c): dia3/6, dia4/9, ...