Hi, I need to define Web @Mercator values for a specific region in Los Angeles to apply to the USEPA's AirNow Map. AirNow recommended this ArcGis tool to identify the Web Mercator values - http://help.arcgis.com/en/webapps/flexviewer/extenthelper/flexviewer_extenthelper.html. However, the site no longer works because of the Adobe Flash retirement. Any suggestions how I can get the Web Mercator values? I am a novice ESRI user. Thanks!
https://www.airnow.gov/custom-airnow-maps/defining-your-map-area
"If you want to change from the default display of the lower 48 to a specific location, you can specify that in the URL using values for the west, south, east, and north edges of the map you want. The AirNow map (provided by ArcGIS) uses Web Mercator values (xmin, ymin, xmax, ymax). These values can be obtained using a tool from ArcGIS available at: http://help.arcgis.com/en/webapps/flexviewer/extenthelper/flexviewer_extenthelper.html."
Even a quick google yielded this - JS Extent Helper (davidspriggs.github.io)