Thundershirt’s patent-pending design applies a gentle, constant pressure to a dog’s torso that has a dramatic calming effect for most dogs. SAFE - Applies gentle, constant pressure, similar to swaddling an infant. EASY TO USE - Just put it on and watch the results. No training required. EFFECTIVE - Over 80% success rate as reported by thousands of families, vets and trainers. MANY USES - For all types of anxiety, fear, and over excitement issues. Anytime calming may help, a ThunderShirt may help. SCIENTIFICALLY STUDIED - Independently by Dr. Temple Grandin and other scientists. DRUG-FREE - No medications... just safe, comfortable pressure. POSITIVE SOLUTION - Most dogs love to wear ThunderShirts! INEXPENSIVE - A fraction of the cost of medications, training... or destroyed furniture! COLOUR: Heather Grey Thundershirt Size Guide: XX-Small – Weight: under 3.2 kg (under 7 lbs); Chest: 23–33 cm (9″–13″); Breeds: Chihuahua, Pomeranian, Yorkshire Terrier X-Small – Weight: 3.6–6.3 kg (8–14 lbs); Chest: 33–43 cm (13″–17″); Breeds: Cairn Terrier, Mini Dachshund, Border Terrier Small – Weight: 6.8–11.3 kg (15–25 lbs); Chest: 43–53 cm (17″–21″); Breeds: Beagle, Dachshund, Pug, Boston Terrier Medium – Weight: 11.8–18 kg (26–40 lbs); Chest: 53–63.5 cm (21″–25″); Breeds: Whippet, Pinscher, Schnauzer Large – Weight: 18.6–29 kg (41–64 lbs); Chest: 63.5–76 cm (25″–30″); Breeds: Basset Hound, Bulldog, Siberian Husky, Small Labrador X-Large – Weight: 29.5–50 kg (65–110 lbs); Chest: 76–94 cm (30″–37″); Breeds: Large Labrador, Boxer, Doberman, German Shepherd XX-Large – Weight: 50+ kg (110+ lbs); Chest: 94–127 cm (37″–50″); Breeds: Great Dane, Mastiffs, Irish Wolfhound Please Note: If your dog is right on the cusp of the weight range indicated in our size chart, we would generally recommend that you size down.