In order to buy a couple of these bottles without paying an arm and a leg for shipping costs, I purchased 10 from US Plastics, at about the same shipping cost as two would be. So, I now have 4 extras. They are almost identical to the 500 ml bottles that Tropica Plant Nutrition Liquid comes in. They hold 500 ml or 16 oz of fluid and the dosing chamber is marked for 5, 15 and 30 ml, and 1/2 and 1 ounce measures.

I will sell them for 2 for $10, or 4 for $15, shipping by priority mail included. Selling only one wouldn't be economical for you. PM me if interested.