set flexslider to fixed height?

I have build a site http://dgdesk.com/bron/ where the images are wobbling in the flex slider. It’s not a lot, but enough to be bothersome. Is it possible to fix the height of the slider?

Hi Jos,

I hope you are well today and thank you for your question.

You can try achieving this by regenerating the thumbnails on your site using the following plugin.

Best Regards,
Movin