Designed by Kimberly Morgan, pattern available in her Esty shop. https://www.etsy.com/listing/1099331749/jordans-arrow-pen-cover-pattern-odd Many of her patterns use size 10 Delicas.
Odd count peyote

Size 10 Miyuki Delicas - Colors used
DBM-704 - Red Transparent
DBM-854 - Yellow Trans Matte
DBM-883 - Cream Matte Opaque AB
DBM-879 - Turquoise Blue Matte Opaque
DBM-010 - Black Opaque

White beading thread - Nymo??
Pilot G2 Pen