Both sides can be used. Provide a safe stand for round bottom flasks. - Very soft and easy to clean. - Resistant to chemicals. - Good thermal and electrical insulation. - Excellent adhesion to glass. - Non-slip. Available in 2 qualities: - Rubber, black. - Silicone elastomer, blue, oxidation-resistant, temperature-resistant from - 60 to + 200 °C. Both sides can be used. Provide a safe stand for round bottom flasks. - Very soft and easy to clean. - Resistant to chemicals. - Good thermal and electrical insulation. - Excellent adhesion to glass. - Non-slip. Available in 2 qualities: - Rubber, black. - Silicone elastomer, blue, oxidation-resistant, temperature-resistant from - 60 to + 200 °C.