How to make SS vacuum flask？

Sun Glory Group is with factories of 50 years experiences,total 600 staffs,70 R&D engineers,55 service engineers In pass 6 years，we have set up more than 66 stainless steel bottle and thermos flask production lines for customers in India,Turkey,Spain,Mexico,Bengal etc.... and cooperate with Top 10 International ss bottle flask brands. Welcome to contact Derek Sunglory for more details，SunGlory is your . Derek Sunglory Whatsapp： 86 138 2224 0712 Email ：sunglory15@