CHEMICAL RESISTANT - PTFE material can be used with chemicals, including acid and base POWERFUL - PTFE casing helps reduce friction and wear while spinning EASY USE - Place inside a container of liquid that is seated on a magnetic stirrer PORTABLE suitable for WIDE USE: perfect suitable for stir a liquid or solution in scientific research, industry, agriculture, health and medicine, homebrew, etc Model Number: STIR BAR Colour:White Material:PTFE Types: B Set Package Contents: 1 x 10mm x 4mm stirring rod, 1 x 15mm x 6mm stirring rod, 1 x 20mm x 7mm stirring rod, 1 x 25mm x 7mm stirring rod, 1 x 30mm x 7mm stirring rod, 1 x 30mm x 8mm stirring rod, 1 x 35mm x 8mm stirring rod, 1 x clip Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.