3 Methods of control [TIM,EXT,BYP], {outside basic timer, external wireless control w/freq switch or bypass (just passes water right through it)}
A. outside timer can be used for just a timed watering of the lawn (ie: 2 hours)
B. external mode allows a time range to be set to turn unit on or off using the standard x10 wireless controller, a frequency setting on the timer itself can be used to further limit the days it will run.
(for example: if I wanted to run the sprinkler from 12mid to 5am, 2 days a week, I would set the frequency on the timer to 2 (for every 2 days) (options would be 1,2,3,4,5,6,W), W being weekly, then I would set the x10 timer to turn on the device between 12mid & 5am every day [while it gets the message to turn on every day from the x10 unit, the frequency control on the timer only lets it run the day range specified]. This is great when going on vacation, especially if you are growing grass.
C. This is my favorite feature: how many times I remember having to step out into puddled water, half asleep, throwing clothes on, just to turn off the water. Would be so much easier if I could just use the wireless controller to do it.
D. Bypass mode: just allows the water to pass uncontrolled so the timer does not have to be disconnected.
The device would have a snap in rechargeable battery pack (the same kind a cordless phone uses) within a waterproof compartment (which would also likely house an internal antenna for wireless reception as well), the cover would have a rubber gasket around it to keep it sealed off from water.