I can only find 660nm on Amazon ;-)
https://www.amazon.com/ABI-Light-Therapy-660nm-Infrared/dp/B07SH39YT4/ref=sr_1_1_sspa?keywords=670nm+red+lights&qid=1638312742&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFQMTZHNkVBWFZGRkImZW5jcnlwdGVkSWQ9QTA0ODQ1MDkxQzYxTlNZRFVMRkdCJmVuY3J5cHRlZEFkSWQ9QTAyMTkxOTIzME5ISUtaTVg4V0VUJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==