Sotnos Yellow Block Dog Collars. The Sotnos Yellow & Blue Colour Block collar is super bold, bright and eye-catching! The bright colours will definitely stand out in a crowd and will be sure to brighten up even the cloudiest of days.. This collar has a matching lead available too, the perfect pair!. Complete with a black chrome embossed tag, lead loop & buckle.. These collars are made from PU leather which is super durable, waterproof and easy to clean!. Sizes:. Size. Width. Length Range. Â Small. 15mm. 210-260mm. Medium. 15mm. 260-340mm. Large. 20mm. 330-440mm. EX Large. 25mm. 390-520mm