CREATE TABLE table_name_43 (earpads VARCHAR(255), succeeded_by VARCHAR(255), construction VARCHAR(255), sensitivity__db_ VARCHAR(255))
What are the earpads of the headphone with a plastic construction, an unknown sensitivity, and was succeeded by sr325?
    
SQL: SELECT earpads FROM table_name_43 WHERE construction = "plastic" AND sensitivity__db_ = "unknown" AND succeeded_by = "sr325"