maintenance free造句怎么写

High precision dynamic balancing machine has the characteristics of low noise, high efficiency, long service life, and fully enclosed in high performance grease, life-long maintenance free.

We provide door-to-door delivery installation debugging and one-year maintenance free of charge and all-life services.

The inserting pin with fixed structure which does not need oiling is pollution free and maintenance free.

The press has been designed as a maintenance free product. All the load points use special non-lubricated bearings.