A: Horus-Harpocrates sitting to left on lotus flower with knees drawn up. On the flower two buds; baseline indicating primeval mound? His right hand raised to his mouth, his left holds a flail. A long side-lock of youth is falling to his neck, on the top of his head a lotus crown. On both sides of the crown eight-pointed stars. Around the figure: five characteres or letters.
B: Inscribed in four lines: κρα|θου|αθια|ωι → variant of κρατουαθ, vocales including Ἰάω.
A praxis known from a papyrus (PGM LXI 1-38) specifies that love charms had to be incised with the image of Horus on a lotus flower and the magical name Abraxas. Pieces with the Horus-scheme used as love charms: CBd-533, CBd-534.
Bibliography
Michel, BM on CBd-508
The British Museum Collection database on CBd-508