This is a Round AE Hemi-obol of Maues, the Indo-Scythian ruler. The coin is similar to the tri-chalkon of the Bactrian monarch Demetrius I, although Maues's coin is smaller in size and weight.
Weight: 9.76 gm. Diameter: 26.6 mm
Obv. Elephant head right, with raised trunk, bell around neck,bead and reel border around.
Rev. Caduceus, Greek legend: at right: BAΣIΛEΩΣ at left: MAYOY, monogram in left field (obliterated in my coin).