The S1 belt model is 2GT-9 belt, the single length is 1345mm, and there are three belts on the T1 machine.
Generally, it depends on the frequency of printing. If the machine is used frequently and for a long time, it is recommended to check the tightness about 15 days. If it is not used frequently, check and adjust it when the print quality changes.
H3.0 Allen wrench