What is the filter size of imgaborfilt()?

I am trying to filter several images using Gabor Filters for pre-processing.

I am using gabor() to create the bank of filters and imgaborfilt() afterwards, to apply the filter to the image. However, it seems that you are not able to change the filter size. How does imgaborfilt() filter the image? What's the kernel size?

Haven't found any more info Googleing it.

Thanks in advance.