Most modern avionics stacks have one. Examples: - https://www.garmin.com/en-US/blog/aviation/blue-button-helping-keep-blue-side/ https://www.garmin.com/en-US/b

Most modern avionics stacks have one. Examples: - https://www.garmin.com/en-US/blog/aviation/blue-button-helping-keep-blue-side/ https://www.garmin.com/en-US/blog/aviation/blue-button-helpi... - https://pilotsupport.avidyne.com/kb/article/50-dfc90-wings-level/ https://pilotsupport.avidyne.com/kb/article/50-dfc90-wings-l...