This Wool Fibre Carpet Underlay is manufactured using 100% recycled fibres and can be 100% recycled after it's use too making it very eco friendly. This underlay also boasts a low carbon footprint due to the fact no added chemicals are used to produce it. This Wool Carpet Underlay is 12mm thick providing good comfort underfoot and it is also a brilliant natural insulator, featuring a 3.5 TOG Rating. Not to mention it's 36dB impact sound reduction rating!