I have 5 sizes; as far as I can tell by studying them and the paperwork, I don't have one that takes a 2-1/2" wide strip. The biggest (50) takes a 4" wide strip and feeds out 2" folded. The next size down (25) takes a 2" wide strip and feeds out 1" folded. I've had them for several years, so possibly there is now a size that takes a 2-1/2" strip, to feed out at 1-3/4". The information above on the sizes 50 and 25 might help you in your search.