Synchronous siv yog lub nplhaib-zoo li tus hlua hlau xo lossis iav cov roj av, yog li ntawd nws koom nrog cov hniav tawv pulley. Synchronous siv tus mob, muaj tseeb kis tau sib piv, lub zog me me, thiab kev siv roj ua kom zoo, thiab kev tiv thaiv dav dav, thiab kev tiv thaiv dav dav,
Pom zoo:
CR: SN121; Sn121; SN123; SN111; SN231; SN232; SN232; SN321; SN322; SN322;
Hnbr Compound.