Harmony Contact Blocks Direct assembly on the base plate or another body via integral ratchet Energy limiting snap-on varistor module (230Vac) available, stock no. 610-3004 Standards CSA C22-2 No 14 EN/IEC 60947-1 EN/IEC 60947-5-1 EN/IEC 60947-5-4 EN/IEC 60947-5-5 JIS C 4520 UL 508 Schneider Electric ZB4-B & XB4-B Harmony® 22mm Range