The Flexi Retractable Leashes Never Slacken, As They Are Always Subject To Sufficient Tension. With The Help Of The Intergrated Braking System, The Animal Is Always Under Control. In Addition, A Lock Button Can Fix The Length Of Leash When Walking 'To Heel'. The Classic 1 Has A 5M Cord And Is Suitable For Small Dogs Up To Approx 12Kg.