Trail running, road running, cross country running.. when your dog just wants to run, GOTO1 harnesses are the choice. MATERIALS Regenerated polyamide from fishing nets Regenerated polyester from plastic bottles Inside ECO foam Accessories ocean waste recycled plastic Products containing SEAQUAL® YARN. FUNCTIONSpecially designed for dogs who love running. SIZE chart- the most important is to measure that the harness fit the neck (A) and chest (B). BREEDS SIZE example- XS: Jack Russell, Parson, Sheltie, Border Terrier S: Parson M: Spanish Water Dog, Irish Terrier, Border Collie L: Dobermann. Size Neck (A) Chest (B) XS 25 - 38 cm 36 - 43 cm S 31 - 50 cm 43 - 56 cm M 43 - 55 cm 56 - 74 cm L 53 - 75 cm 72 - 90 cm XL 68 - 89 cm 80 - 100 cm .