1850
The topology optimization result is visually impressive , the performance of this caliper has been validated in various tests and is used in production vehicles , with a 40 % mass reduction compared to the previous version made of aluminium .
 engineering feature: topology optimization; concept or principle: performance; machine or equipment: caliper; manufacturing process: production; concept or principle: reduction; material: aluminium
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 engineering feature: topology optimization; concept or principle: performance; machine or equipment: caliper; manufacturing process: production; concept or principle: reduction; material: aluminium