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 FOR WIDE USE: perfect 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: C Set Package Contents: 4 x 10mm x 4mm stirring rod, 4 x 15mm x 6mm stirring rod, 4 x 20mm x 6mm stirring rod, 4 x 25mm x 7mm stirring rod, 8 x 30mm x 7mm stirring rods, 4 x 35mm x 8mm stirring rod, 4 x clip Only the above package content, other products are not included. Note: Light reflection 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.