The Dog With A Mission Urban Blue Star Dog Collar XXXS is the extra-extra-small version of the premium handcrafted leather collar from the Urban Blue Star collection. It features durable leather and a soft padded interior for everyday comfort and style. The XXXS size is suitable for very small dogs with a neck circumference of approximately 15 – 21 cm and includes a sturdy metal buckle and leash attachment ring for a secure fit.