Size Attention - Make sure to measure your dog’s neck before placing an order. Then refer to the sizing chart: Small 11" – 14.5" | Medium 14.5" - 19" | Large 19" - 23" | X-Large 23" - 27" |. DON'T CHOOSE SIZE BY WEIGHT AND BREEDS ONLY. Dog collar should be snug enough to fit two fingers between the dog's neck & collar