Fed up with unreliable electronic timers I went back this electromechanical type. Easy to install and set. Only disadvantage is each tab represents a 2 hour time difference, so it’s not possible to set on and off times accurately. It also seems to switch on and off at slightly different times each day. On Monday, it switched off at 17.35, on Tuesday 17.59, despite the same on/off tags being set. Fine for something like a light timer but not so good if you need accuracy.
It's ok but timings can only be set in two hour segments and it's a bit hit and miss setting the time accurately. But it does the job in that it stops my water heater coming on at night.