Thule Dart martingale collar - Adjustable martingale collar designed to help prevent slipping while staying comfortable for everyday use. Features • Martingale opening — Martingale opening provides a gentle secure fit that tightens slightly if your dog pulls helping prevent slipping without choking • Enhanced visibility — Reflective webbing and logo improve visibility in low light for safer walks • Size adjustment — Adjustable design for a precise comfortable fit • Padded sleeve — Soft padded sleeve cushions the neck to reduce pressure chafing and irritation while giving the collar a premium feel • Standing D-ring — Upright D ring makes leash attachment fast easy and tangle free for smoother walks Specifications • Dog neck: 13.8-20.5 in • Model number: 771217 • Weight: 0.11 lb • Country of origin: Indonesia