This pattern was designed for the 24 peg large gauge round loom. No gauge is listed in the details, since exact gauge is not crucial to this project.

Update:
Lorie Nicolaus has posted a video, Sunflower Coasters: Loom Knitted, which is based on my pattern and demonstrates how to make the Sunflower Coasters. Hopefully, this will be helpful for those who need a visual demonstration.