The Cambodian currency is composed of riels (5 letters), riel (4 letters), lonnol (6 letters), laos (4 letters), nol (3 letters), THAI (4 letters) and sen (3 letters). Riels are the official currency of Cambodia, and have been in use since the mid-1800s. The riel is divided into 100 lonnol, and is also used in Laos and Thailand. Nol and sen are subunits of the riel, with 1 nol being equal to 10 sen.