The item for sale is 4 Ounces of Sodium Sulfite (Na2SO3), also known as Disodium Sulfite. Sodium Sulfite is a soluble sodium salt of sulfurous acid. It is commonly used as a preservative or to convert elemental halogens to their respective hydrohalic acids. For Sodium Thiosulfate, check out our other listings. STURDY PLASTIC BOTTLE: Our bottles are made of durable Polypropylene Plastic, which is a natural, translucent, lightweight, durable, and chemically resistant copolymer. The screw-top is completely leakproof. The bottles? round shape makes them a perfect addition to any shelf or travel kit. Every bottle we ship is sealed in plastic with the screw-top shrink-wrapped. HUNDREDS OF USES INCLUDING: Food Preservative / Paper Pulp Treatment / Water Treatment / Oxygen Scavenger Agent / Photographic Processing / Textile Bleaching / Dechlorinization Agent / Froth Flotation / Leather Tanning / Oil Recovery / Chemical Manufacturing / Dye Making. SHIPS FAST FROM CALIFORNIA, USA: We ship three times a day, seven days a week. This item will be in the mail the same day you place your order. By itself, this item will ship in a padded bubble-mailer (2-5 day transit time). Combined orders exceeding 13 ounces will be upgraded to a flat-rate box (1-3 day transit time) at no additional charge. Please make sure your stated shipping address is correct, complete, and unambiguous. Applicable products are packaged and shipped in accordance with carrier regulations for ORM-D classification.