How to distinguish 304 stainless steel and 201 stainless steel thermos
Consumers know 304 stainless steel vacuum cup is good, 201 stainless steel vacuum cup is not good, of course, 304 vacuum cup is higher than 201 vacuum cup price. But by 304 stainless steel or 201 stainless steel vacuum cup is difficult to distinguish the average person, gave some black enterprises the opportunity to use…