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
L8-01-B05, Block B, Baocubic Jewelry City, 198 Xin'ansi Road, Liutang Community, Xixiang Street, Bao'an District, Shenzhen, Guangdong, China