Schneider Electric XB4BA42 Harmony XB4 red flush pushbutton 22 mm spring return 1 NC. The Schneider Electric XB4BA42 is a Harmony XB4 complete pushbutton in chromium plated metal with a Zamak fixing collar and 22.5 mm mounting diameter. The XB4BA42 uses a red flush unmarked operator with spring return and a single slow-break NC contact with positive opening conforming to IEC 60947-5-1 appendix K, which is why it is chosen for stop commands. Ratings include 10 A conventional free air thermal current, 600 V rated insulation voltage, 6 kV impulse withstand, silver alloy (Ag/Ni) contacts, screw clamp terminals and 10,000,000 cycles mechanical durability. The unit is sealed to IP66, IP67, IP69 and IP69K and operates from -40 to 70 degrees C.