The Dog Helios 'Arctic Blast' Full Bodied Winter Dog Coat is Inner-lined with exclusively developed Blackshark Technology, this innovative fabric is Lightweight, Waterproof, Windproof, Snowproof, Breathable, Cold-Repellent, Impermeable and Tear Resistant. The Outershell is further Waterproof treated and the Inner-shell is composed of Anti-Static warm Polar Fleece that hugs the body. Geared with a Removable and Adjustable Hood that extends over the Head and Ears with a Jawstring that seals coverage for head-extremity protection. Sizing Guide: From Back of Neck to Tail area ("In" Inches): 8" : EXTRA SMALL, 10-12": SMALL, 14-16": MEDIUM, 18-20": LARGE, 22-24": EXTRA LARGE. Sizing Specifications: (In Inches): XS: 8.3" Length, 17.7" Chest Girth, 12.2" Neck Girth, SM: 11.8" Length, 21.7" Chest Girth, 13.7" Neck Girth, MD: 15" Length, 24.4" Chest Girth, 15.8" Neck Girth, LG: 18.9" Length, 29.9" Chest Girth, 16.9" Neck Girth, XL: 22.8" Length, 34.7" Chest Girth, 18.9" Neck Girth.