Dimensions (L x Ø): 20 x 10 mm Elliptical magnetic stir bars are well-suited for use in round beakers. The elliptical form ensures homogenous mixing. Minimal contact when used in plastic containers. The PTFE coating is chemically inert and resistant to aggressive chemicals. Dimensions (L x Ø): 20 x 10 mm Elliptical magnetic stir bars are well-suited for use in round beakers. The elliptical form ensures homogenous mixing. Minimal contact when used in plastic containers. The PTFE coating is chemically inert and resistant to aggressive chemicals.