Tap timers are simple battery-operated controllers. Most of the time they operates one zone, but there are tap timers for more zones as well.
The are mounted after the first main isolator.
There are different tap timers on the market. We advise to look into the User manual.
They are operated by batteries. Usually the batteries last one year, so they should be replaced prior to start of the season.
Tap timers contains metal and plastic parts and small channels hence they are not frostproof. At winter shutdown they must be dismantled and stored in a dry, frost-free place.