The SSTC1 is a single channel for bell times, Bell duration 1 to 9 seconds, Max 140 programmable times per week, 24 hour clock format, auto correction for leap years & daylight saving, 6 key function for total operation, Manual on/off bell output, 240v AC supply, 250 hour battery backup, LCD readout, standard wall mount, Dimensions - 130H x 85W x 60D.