From the pattern description:
This sweet pink version of the secret-keeper socks is made for a slightly younder child. Here, the pocket is picked out in a pretty purple yarn. This version is knitted to the same basic pattern as the Jungle Explorer Socks, but uses a lighter weight of yarn and smaller needles, so the finished item will be smaller and therefore fit a younger child

Addition Yarn Information
2 x 1 3/4 oz (50g) balls of light-weight (DK) wool yarn in pink
1 x 1 3/4 oz (50g) ball of light-weight (DK) wool yarn in purple

Notions
2 stich holders
2 snap fastners