The Tree Mat is made from dry Natural Rubber from the Havea Brasiliensis tree, on a 100% cotton mesh. Natural rubber and cotton are degradable making this an ecologically sound yoga mat. The Tree Mat also has the best grip, which combined with good shock absorption and abrasion resistance make this mat unbeatable. Tested by SGS Laboratories as Heavy Metal & AZO Free and as safe for "food contact substances."to FDA Requirements. Washable - air dry avoiding sunlight 183cm x 60cm x 4mm. Rounded corners. 1.6Kg Double sided mat with either Black top and Green bottom, Blue & Slate or Aubergine Top and Lavender bottom Please note: As the colour of natural rubber vaires considerably from batch to batch, this affects the finished colour of the mat also so colours may be lighter or draker from those shown.