Schneider Electric Acti 9 IHP - Digital Time Switch Acti 9 IHP series of digital programmable time switches. They are used to program automatic operation of heating, lighting and ventilation. Digital time switch 24 hours / 7 days Minimum switching time 1 min. Automatic winter/summer time changeover Operating hour counters Absence for holiday function LCD display PIN code Version IHP (stock-no. 841-7737 , 896-8579 , 896-8581 ) - Number of switching: 56 Version IHP+ (stock-no. 896-8588 , 896-8585 , 896-8594 ) - Number of switching: 84 - Pulse programming - External input for override Relay output IP20B protection DIN rail mounting Note Memory key and Programming kit are sold separately.