iGS618 /620/60 supports to connect sensors with ANT+ function.
It has been tested that following power meters are supported:
Stages, Power-tap, Quaq, SRM, ROTOR, Garmin Vector, Power2max, Pioneer, 4iiii.
Some clients say that the device doesn't support Garmin Vector only, and we haven't checked that.
Other power meters haven’t been tested, you can have a try if needed.