These tea bags are bio degradable and cause no pollution. Ways of seal off: seal it off by string. No using hot iron or electric iron. These bags are used for filling with 3 ~ 8g mixture of tea or dry herb or plants. Suitable for tea, spice and herbal powder. Feature: Brand new and high quality These tea bags are bio degradable and cause no pollution Ways of seal off: seal it off by string No using hot iron or electric iron These bags are used for filling with 3 ~ 8g mixture of tea or dry herb or plants Suitable for tea, spice and herbal powder Size: 5.5 x 7cm Material: Non-Woven Fabrics Color: White Package included: 50 x Empty Tea Bags