1. Three-stage design：This type of jack has three telescopic sections or "stages" that allow it to stretch between a compact initial height and a high maximum lifting height. This allows it to adapt to different vehicles and lifting needs.

2. Pneumatic operation: 

By connecting to a compressed air source (such as an air compressor), pneumatic jacks can be raised and lowered quickly, reducing the labor intensity and time of manual operation.

3. Heavy load capacity: 

Usually has a high load capacity and is able to lift heavy vehicles such as trucks, vans, etc.

4. Safety: 

Many pneumatic jacks are equipped with a safety locking device to ensure stability and safety when lifting heavy objects.

This equipment is widely used in auto repair shops, garages, and industrial environments to lift and support heavy equipment and vehicles.