D-400 double wall glass mug 1.SGS certificate 2.super transparent 3.heat resistance ... etch logo Shanghai linkand co.ltd.manufactory the glassware and pocelain mug .We have more than 10-year experience in these ... ,beer glass, shot glass, drinking glass.whisky glass ,ceramic mug. glass tempery plate, tea glass, glass cup, and glass ... press machine and some are by mouth. Ceramic mug are all made by hand.