Aerator threads won't fit

[Vaportrailz]

I have a Fresca Tolerus faucet and need a new aerator. The diameter seems to be 13/16 in but the threads on the replacement seem to narrow for the threads on the faucet. Cant find a replacement that fits. Any thoughts?

 

[breplum]

Plumbing supply shops and even some good hardware stores have sample boards with threads to help match up various threads since there are quite a variety.