Contact block, 1NC+1NO, break before make. range of product: OsiSense XC – series name: special format – product or component type: limit switch contact block – device short name: ZC1A – product compatibility: XC1AC12. – contacts type and composition: 1 NO + 1 NC – contact operation: slow-break, break before make – contacts material: silver plated contacts – positive opening: without.