Sure Sired Marker Crayons are bright, durable and fully scourable. They are available in six colours, and in two climatic compounds to suit all types of weather conditions. Developed to provide a longer life and to mark more ewes per block, each crayon is presented in a patented plastic crayon container that will not rust and is designed with a 90o angled ski to avoid damage to the ewe if the crayon is worn down to the carrier. Each crayon is designed with an original split pin for secure holding in Net-Tex harnesses. Hot-hard , suitable for temperatures in excess of 85 degrees (30 degrees Celsius) Mild-medium suitable for temperatures in the range of 60F -85F (15C-30C