Need Diameter of Shimano E-Tube Di2 Internal Junction-A EW-RS910

Does anyone know the diameter of the EW-RS910, the portion that goes inside the bar end?

I just want to make sure it will fit my handlebar before I commit. Thanks.

E-Tube_Di2_Internal_Junction_A.jpg

https://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/DIY_Shimano_EW-RS910_di2_junction_box_into_aero_extensions_P6242355/?t=csrrgllpwzkhwr
.

Thanks for the link, which has the info I was looking for.

About 19mm
.