Description of Ruff Wear Approach Pack™ This pack was designed to be an everyday pack with excellent performance, fit and functionality. Comfort-fit Web Master™ Harness frame ensures good structure, stability, and load dispersion. The five-point adjustable fit accommodates dogs of all shapes and sizes. Good for one-hour to three-day hikes. Use to offset your load or for training and exercise. The Approach Pack gives your dog a load to carry and a job to do, generating instant four-legged motivation. Features: Attached saddlebags with lightweight, streamlined, go-fast shape Weight-forward saddlebag design for ideal load-carrying position Trail-savvy details like waterproof zippers, high-visibility reflective trim, external gear loops, and durable construction Comfort-fit Web Master™ Harness frame ensures good structure, stability, and load dispersion Five-point adjustable fit to accommodate dogs of all sizes and shapes Designed to be worn with padded comfort, secure fit, generous ergonomic cut, and full range of motion The pack’s harness should have an all-around snug fit for a stable load and to prevent movement or shifting of the saddlebags. Be sure that each saddlebag has an equal and balanced load. XXS 12"-19" 30-48 cm 122 cu. in. 2 L XS 17"-24" 43-61 cm 305 cu. in. 5 L S 21"-30" 53-76 cm 549 cu. in. 9 L M 26"-36" 66-91 cm 732 cu. in. 12 L L 32"-48" 81-122 cm 976 cu. in. 16 L Girth: measurement around widest part of rib cage Performance fit: contoured, athletic cut In-between sizes: Choose the smaller pack for a lighter load and less bulk. Please do not use saddlebag capacity as your only sizing consideration; use the girth fit for best results.