DescriptionCobalt glass is a special filter glass, mainly used in chemical laboratories to observe fire through potassium flame reaction. It is also used in many places in industry, such as cement plants, steel plants, and industrial kilns.Features- Color: Random color.- Material: Glass. - Size: 5.50X5.50X0.50cm/ 2.16X2.16X0.20in. - Cobalt glass is a special filter glass, mainly used in chemical laboratories to observe fire through potassium flame reaction. - It is also used in many places in the industry, such as cement plants, steel plants, and industries. - The special filter glass is an indispensable object in the chemical flame color reaction, and is a good helper for your experiments.. - Observing the color of the flame through the cobalt glass sheet can determine whether it contains potassium.. - Exquisite workmanship and creative appearance ensure its popularity and practicality.