Nyob rau hauv qhov kev txiav txim ntawm ib tug sab nraud quab yuam (mechanical quab yuam los yog kua siab), lub annular gap yog kaw los tiv thaiv cov kua los ntawm machinery.
Peb paub zoo tias yog ib qho ntawm cov khoom lag luam thiab cov muag khoom hauv Suav teb. Thov koj xav tias dawb mus yuav cov khoom ntim khoom customized ntawm tus nqi sib tw los ntawm peb lub hoobkas. Yog xav paub ntxiv, tiv tauj peb tam sim no.