Which clip is the most widely used in chemistry experiment classes in elementary and middle schools?

Which clip is the most widely used in chemistry experiment classes in elementary and middle schools?

We are a factory specializing in the production of metal products in China. The inside of the metal clamp for teaching, this two-jaw clamp is the largest purchase by European and American customers.

Which clip is the most widely used in chemistry experiment classes in elementary and middle schools?-MasterLi, Кытай заводу, жеткирүүчү, Өндүрүүчү