From the Knit Rowan website:
Knit this accessory beret or tam, a design from the Rowan archive that is now available to purchase online. Designed by Sarah Hatton using the beautiful yarn Cocoon (merino wool and kid mohair), this slouchy pull on beret has garter stitch detail.

Finished dimensions:
Completed beret is designed to fit an average woman’s head.

Yarn information:
Photographed in 813 Seascape
1 skein
126 yards