This 20" gardener's thermometer is made of corrosion-resistant stainless steel. The compost thermometer is perfect for measuring the heat core of your compost tumbler and helps you to maintain maximum heat . This allows for the best decomposition of compost materials. Use this compost thermometer to maximize and stabilize your compost as you process your ingredients in your compost tumblers.. You will also find it useful in checking soil temperature in your garden as you get ready for different planting seasons. Shipping Via FedEx Ground. Shipped to the 48 contiguous United States only. For rates outside the contiguous US, please contact us