STC, launched free service named (Ishaar), which is a tone designed to alert customers when contacting a number outside the network.
The tone will be heard in the beginning of the call. The service is available for postpaid and prepaid customers for free. It can be activated through MySTC, or by sending 1313 via SMS to 900, or cancellation by sending 1319 via SMS to 900.
Source: STC Press Release