You sure can. Our filters are double threaded so you can stack filters to your heart’s content.
All our filters are double-threaded, which means they have back and front threads so you can stack filters of the same thread size. The exception to this rule is the Variable ND filters, which require a larger filter to be stacked on top. E.g. a 58mm Variable ND takes a 62mm thread size on top. However, we recommend you avoid stacking any filters with the Variable ND filter range as it can create vignetting.
Remember that stacking too many filters together can cause vignetting so we would not recommend stacking more than 2 filters together. Some popular stacking combinations include combining 2 fixed ND filters for a greater ND filter factor, and leaving a UV on your lens and stacking a CPL or fixed ND on top. Remember that you will always get the best image quality with just one filter on your lens.