Reformed Umayyad silver dirhems do not name the Caliphs, but the coin are dated which tells us under which Caliph they were struck.
Denomination : Silver Dirhem. Mint : Wasit.
Date : AH 120 (AD 738)
Reference : Mitchiner Islamic - 60.
Size : 28.5 x 28.9 mm. Weight : 2.90 grams.
Grade : XF
Obverse and Reverse : Arabic inscriptions.