Stair light timer switch with pre-warning for switch-off and optional permanent light via button. Standby loss is only 0.7 watts. Features ESL optimization and multifunctionality. Contact switching at zero crossing to protect contacts and lamps, which particularly extends the lifespan of energy-saving bulbs. The use of a bistable relay ensures there is no coil loss and no heating even when switched on. After installation, wait for the automatic short synchronization before connecting the switched load to the power supply. Additionally, it has galvanically isolated universal control voltage. Automatic detection of the switching type. Glow lamp current up to 50 mA, depending on the ignition voltage of the glow lamps. Precise time setting from 1 to 30 minutes with a minute scale. Permanent light switch with a large rotary switch. After a power failure, in the function setting TLZ, the lighting will be turned back on if the time has not yet elapsed. It has double connections for the button and lamp, allowing for connections at the top and bottom or just at the bottom. When the switch-off pre-warning is activated, the lighting flickers about 30 seconds before the time elapses, starting with a total of 3 flickers at decreasing intervals. When the permanent light via button is activated, it can be set to permanent light by pressing for more than 1 second, which will automatically turn off after 60 minutes or can be turned off by pressing for more than 2 seconds. If both the permanent light and switch-off pre-warning are activated, the switch-off pre-warning will occur only after the permanent light is turned off.