Change Thumb SIze Under Main Image

On the product description page, the images below the main image is really tiny. How do I change the size of those images?

The smallest size that I have for images under Files/Images is 120px x 120px. The images on the product description page is alot smaller than that - so I'm not sure where that size is coming from.

Thank you!!

Here is the solution:
www.hikashop.com/en/support/documentatio...ling.html#thumbnails

BIG thank you!!