40-hour XL Heat pack for plants...After opening the package the oxygen of the air reacts with the iron powder inside the warmer and after a few minutes heats up. Your heat pack will place in your plant box, keeping your plants all snug! The warmer will generate heat for about 40hrs.
Size: 15,5 cm x 11 cm
Duration time ( h ): 40
Temperature (Max. / Avg.): 52°C / 46°C
Ingredients: Iron powder, water, activated carbon, vermiculite, salt