This Medium Dog Harness Fits Narrow Body Dogs With A Deep Rib Cage. The Soft Reflective Chest Strap, Flexible Saddle, And Ultra Soft Webbed Girth Keep The Dogs Range Of Motion Flexible While The Reflective Outline Keeps Them Visible. Thus, Making It A Great Athletic Dog Harness For Nose Work, Disc Dog, Flyball Or Any Other Canine Sport That You And Your Pup May Be Involved In. Have Fun With The Coolest Medium-sized Dog Harness In Or Out Of Town. harness Measuring 1) Front Measurement – From The Breastbone To The Middle Of The Back. 2) Girth Measurement – The Circumference Of The Dog At The Middle Of The Back. once You Have Your Measurements, See Dog Harness Size Chart : medium-sized Dog Harness – Lucy Fit: #1 Front: 11”-14” – #2 Girth: 21”-29” – Approximate Weight Range 17lbs To 30lbs – Ideal Dog Harness For Border Collie, Belgian Malinois, Shetland Sheepdog, Greyhound whats In The Box 1 Medium Dog Harness 2 Removable Brilliantk9 Embroidered Patches colors: celebration crazy Hearts fototasmic galactic Splash mystic Moor optic Orange passion Fire red Rock Jaguar serengeti star Chief tribute tropic Treasure black Knight cobalt Blue cosmic Pink forest Green grape Purple lipstick Red neon Green neon Pink neon Yellow royal Purple safety Orange tahiti Blue