RTK Units on Mission Planner

Hi I’m new to using Mission Planner and I was wondering what the units the RTK altitude, latitude, and longitude are in? MissionPlanner says ECEF but plugging in the values into a ECEF conversion calculator gives an error. Is it actually reported in HAE(WGS-84) or MSL? I’m also attaching a photo of the units and values I obtained in missionPlanner.

In practice, I’ve been using WGS84 referenced calculations without issue, but I look forward to the answers here.