Append text to existing tag for all images in a folder

[sargfadrgfvcreadv]

Hi, I was wondering how I would append " with 25mm extension tube" to the LensModel tag for all images in a specified folder. Is that possible?

[StarGeek]

try
exiftool "-LensModel<$LensModel with 25mm extension tube" /path/to/files/

Change the double quotes into single quotes if using Mac/Linux/Powershell