A visit — yours or an inspector's — is the surest check on a new supplier. Send a date and what you want to see; the request reaches them as an enquiry you can track.
Address
Nanjing Yuhuatai District, Guxiong Street Persimmon Tree Industrial Concentration Area, No. 18 Dingjiawa No. 1 Plant, Nanjing, Jiangsu, China