12 people in Mann Hummel Group which is the largest automotive filters manufacturer in the world came to make evaluation on Shandong Renfeng Special Materials Co., Ltd in the end of Feb.2016. Six people were from Mann Hummel Germany and the other 6 people were from Mann Hummel China. They are air filter engineer, oil filter engineer and fuel filter engineer. They visited Renfeng’s workshop for manufacturing filter media from raw materials till the final finished product. They separately made detailed technical communications on air filter media, oil filter media and fuel filter media. They emphasized the importance of stable and reliable quality on filter media to guarantee the filtration performance of their filters. They spent a whole day to evaluate Renfeng company as their new supplier.