TWO 500ml 37% Formaldehyde (total 1 liter in 2 bottles, approx 1 quart) - UPC grade. Pharma-grade glass bottle shipped fast ONLY to lower USA 48 states TWO 500ml 37% UPC lab grade formaldehyde (NOTE: for shipping we had to change to chemical resistant plastic bottles) Formaldehye last centuries for preservation, formalin lasts only about 6 months