Build your own propagator or use as under soil heating in your greenhouse - very economical for large areas. Used by commercial growers, soil warming cables are mains operated, fully insulated, completely waterproof, safe and easy to use (full instructions supplied). Bio Green Soil Heating Cables features: Warms the soil by 8-12 degrees. Manufacturers recommend you use the soil warming cable with thermostat (optional extra, see below). Thermostat provides automatic control for your propagation requirements and more economical use of the cables. Can also be used in terrarium or aquariums.