They have low noise with little vibration but at the same time are light weight and of simple construction. The ML series motor

ML series aluminum housing single-phase induction motor   

The ML Series Aluminium housing single-phase two value capacitor asynchronous motors are the latest design and are made of selected quality materials and conform to the international IEC standard. ML motors have a very safe and reliable performance, are attractive in appearance and can be easily maintained.  They have low noise with little vibration but at the same time are light weight and of simple construction. The ML series motors can be used for air compressor, pumps, refrigeration, medical apparatus and instruments, and other small size machines.

ML series aluminum housing single-phase induction motor(ML711-2)