Using an RE220T Signal Repeater can dramatically improve the reliability of sensors distant from the 2Gig Go!Control Panel, however there are a few things to keep in mind.
It should be placed in the home based on performance, but it will generally go somewhere midway between the distant sensors and where the Go!Control Panel is installed.
It can also be tried in scenarios where supervision errors are common. Consider implementing a Repeater if supervision errors occur on 345mhz sensors and is not otherwise explainable. (In situations where a large number of sensors are being used, often 30+, this may be seen).
The RE220T must be powered via 12v DC transformer.
The RE220T will not repeat life safety signals, so devices like the SMKT3 Smoke Detector will not have their signals improved.
Multiple Repeaters at the same location can create a sort of feedback loop wherein a sensor reports opening, the repeaters pick up that signal, transmit it to the panel and to each other, then repeat the same signal they just sent and received. Do not use two repeaters at one location.