Watch Band

As far as I know 33mm was never a valid case size, did you misread 38mm? The bands now tagged as 40mm for Series 4 will fit 38mm watches from earlier series.

I have not seen anything that small, however, a call to any Apple store should answer your question.

33mm is not a valid size. I imagine you have the 38mm case? If so, it will work with the 40mm straps in the Apple store.

Hope this helps