Another recent purchase is this new dog containment system, from Petco. Several years ago I installed an "invisible fence" type of system, but it has its shortcomings, currently a break in the circuit that I have not been able to find. This new system has its quirks as well, such as the collar issuing a "correction" when I turn off the base unit, so I either have to make sure Betsy is not wearing the collar when I turn off the base unit or simply never turn off the unit. Or remove the battery from the collar.
The Petco system has proprietary batteries for the collar which can be thrown out with the rest of your trash.