Kokubo Stainless Steel Bottle Detergent is for cleaning, sterilizing, and deodorizing stainless steel bottles easily. Each box has six pieces inside. 

Good for use against: Stainless steel, glass, pottery, plastic

Please do not use on:  Iron, copper, aluminum, brass, tin, gold, silver, gunmetal

How to use:

Add enough hot water (about 40 ℃) to prevent the bottle from overflowing. Please a packet inside the bottle. Leave it as it is for about 2 hours. (If it is very dirty,
leave it on overnight). After a while, discard the hot water in the bottle and rinse thoroughly with running water.

Ingredients:

Citric acid (anhydrous), oxygen-based bleaching agent