height thumb slide in gk_image_show

I use the module gk_image_show configured with template the Icki Sport. By cons I put it in full width of the template. Proportionally, so I changed the height of the thumbnails, I spent 80 to 60px.

Now I'm looking for where is the parameter for the DIV down from 88 to 68px for gk_is_thumbs_prev and gk_is_thumbs_slider

Thank you

please show me your site, and a picture of what you want done and i take a look.

Here : http://foot11.sportingfutsal.fr/
you can see the arrows are not in the middle of the height