24886
Some 2010-era lower - to mid-priced basses are made of willow , student models constructed of Fiberglass were produced in the mid-20 th century , and some ( typically fairly expensive ) basses have been constructed of Carbon fiber .
 Fiberglass
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Fiberglass