Determining the correct size for your Service Dog's Vest isn't an exact science. Here at Shark Fin Gear, we strive to ensure you achieve the ideal fit. That's why we offer seven sizes tailored to most breeds, with the exception of the smallest dogs weighing under 15 lbs. Consult the sizing charts provided below to gauge and equip your dog with the appropriate harness. Additionally, once you've placed your order, be sure to watch our instructional video demonstrating how to properly put on and adjust an SFGC harness. Keep in mind that these Service Dog Vests have handles from the front of the harness to the back, parralel with the dogs spine. The come in 3 colors. Sometimes people choose the harnesses in the Outdoor Adventure catagory for a broader selection of colors and a different handle position.