Specifications<br><br> -Size: XS: Chest :13-17inches, fit for weight 9-14 lbs<br> S: Chest :17-21inches, fit for weight 15-25lbs<br> M: Chest :21-25 inches, fit for weight 26-40 lbs<br> L: Chest :25-30 inches, fit for weight 41-64 lbs<br> ¡¡¡¡XL:Chest : 30-37 inches, fit for weight 65-110 lbs<br> -Material: Made of breathable and durable fabric, give the dogs best care<br> -Reflective strip on dogs¡¯ neck for night walking safety<br> -Hoop and Loop design make it easy to put on and take off<br> -Massage particles on the back,give your pet constant care.<br><br> Fitting Instruction<br><br> Step1: Dog thunder vest over the back of your dog, lightly wrap chest strap around the front of the dog and secure with fasteners<br> Step2: Wrap the short flap down on to the long flap and secure with fasteners, adjust for a comfortably snug fit as necessary<br>