These taillights are currently provided by Kaper II.
The part number is: L03-0099
Here's the manufacturer's web page:
Click on view PDF to see the listing for these lights:
If you are within the warranty period and experience a failure with a light, send a description of your symptoms, a photo, and your ship to address to firstname.lastname@example.org, and we can get you replacements. If you are out of the warranty period, contact Kaper via the website to know where you can order some parts nearest you.
- The OGT Warranty dept