Our Scent Discrimination Articles are designed for ANKC training and trials. This pack contains your leather wood and metal articles. Each article will be numbered from 1 to 5. Size guide Leather: 25 x 150 x 6mm Metal: 16 x 16 x 150mm Wood: 16 x 16 x 150mm Based on the rules noted below our articles meet the ANKC UD level requirement for trialling The dye used on the leather articles is water based, low VOC dye called Eco-Flo. Low VOC refers to low volatile organic compounds that are not harmful to the environment and humans. Low VOCs are good for both the environment and living organisms. We actually use that as it imparts very little smell, unlike some dyes. But it has the added benefit of being very safe for your dogs. Scent Discrimination (UD):Scent Discrimination articles must consist of three sets of articles comprising five wooden, five metal and five leather. The articles must be a minimum of 100mm and maximum of 200mm long. The other dimensions must not exceed: wood 18mm square; leather 25mm wide and 6mm thick; and metal a maximum external diameter of 18mm. The metal articles may be knurled but no articles are to be coated or covered with any material. The size of the articles may be in proportion to the size of the dog. Each set of articles must be legibly numbered 1-5 or alphabetically marked A-E and the articles in each set must be identical.