1.Professional Manufactory 2.Block auxiliary contacts 3. Screw Terminals 4. 31E 3 normally open + 1 normally close contacts 3RH1911 3RH auxiliary switch blocks for front mounting on S00 (3RT1015, 3RT1016, 3RT1017) contactors. Contains 2 N.O. and 2 N.C. contacts 3RH1911 AC Contactor