This brush washer has a Kangxi reign mark. But the foot rim doesn't quite look as if it were of that period. However, with pictures it is sometimes difficult to tell. I would need to do a hands-on inspection to check if it could be from the 18th century. In my view this is probably a later copy, possibly mid-Qing dynasty, or first half of 19th century. I would think that it the best item among these in view to collecting value.