SAB Yes, it is. You have to pair both phones the first time you use it... then, you can actively use it on one phone at a time, without having to pair again. :)Follow the pairing instructions to pair 2 phones. :)

SAB Its okay. Some people say I sound okay and others say I sound like a robot. Pair with other phones to make sure your earpiece is really working or not. :)

SAB Si, se puede usar ibus para FlySky RX (Yo solamente vuelo FlySky, y puedo usarlo en el connector RX2).

SAB Sometimes, you have to go to the manufacturers website and download the firmware files directly (if they have BF4.2 for that board) and direct BF to the file for manual firmware update (make sure you get the right one for your board or you can brick your flight controller). Did you confirm there's a BF4.2 available for that board? -or- You may have to update to the new version of Betaflight to get the firmware you want to show up. Make sure you're using the real Betaflight, not the Chrome addon, etc. :)

SAB This answer was incorrect about Wavelength by IMSSK (IMSSK stated general UV wavelength, not wavelength this unit actually uses). This unit doesn't state what wavelength it's really using. I've emailed manufacturer and will update this answer. :)

SAB This fits the standard 1.5mm props. Both numbers you stated will not work on this Tyro89. You MUST use 1.5mm props for least or no vibration (jello) in flight. 1.5mm hole props only.

SAB Yes, this is the normal jst connector for whoops existing in the last 2yrs (as old as Mobula7 whoop).

SAB Nope, the picture is not accurate. I purchased this motor and shaft is 2mm, not 1.5mm. You'll have to get new props for these (I happened to have Lumenier 2.2" 2 blade props that are 2mm shaft hole sized. All my 1.5mm holed props wouldn't fit the 2mm shaft. Was very surprised). Buy new 2mm hole props for these new motors (make sure the props have the T-holesTo screw them down, too). :)