Size 30 crochet cotton. Partially written but completely charted.

First two rounds measure 1/2” in diameter. Intermediate. Double triple crochet (aka double treble) in US terms. Beads added with crochet hook on outer edge only.

Pattern 12, page 27 of Decorative Crochet.
Shown on cover of Puntorama Ganchillo.
Pattern 26, Lysedug, in Haekling 21.