 On urgent dispatches the ekishi would ride with the bells ringing in order to be able to change horses at any time of day or night without delay.These bells were also known as post road bells ("ekiru no suzu") or stable bells ("umaya no suzu").The system was established in the Taihō Code from 701 and was in use until the end of the 12th century or the end of the Heian period when it fell in disuse together with the demise of the centralized state.