Made from white spun polypropylene. Provides up to 3°C of frost protection as a single layer (6°C as a double layer) either outside or in the greenhouse/polytunnel so reducing heating costs. It can be laid directly on top of plants without restricting growth or it can be laid over cloches. It will also protect from heavy rain and wind and will keep out insects and birds while allowing ventilation and natural watering. Used over carrots all year it will give them an early start and also protect them from carrot fly.