Hello
Many thanks for your question,
We have both 3.inch and 5inch wide vertical blind slats,
i am unsure if you are ordering the full vertical or just the slats,
But please find below links direct to the 5inch options we have,
5inch vertical blinds- https://www.blindsbypost.co.uk/vertical-blinds?slat-size=127mm-5
5inch replacements slats only- https://www.blindsbypost.co.uk/replacement-slats?slat-size=127mm-5