Please check the 7th image in the left side of the product web page and part,which will teach you how to train dog to accecpt muzzle.Beacuse dogs are anxious about wearing muzzles at the beginning:try to take off muzzles or bite through muzzles.<br> NEW DESIGN: We add head strap design,which will effectively Prevent from taking off by dogs paw.<br> MEASURMENT:Measure circumference of dog'mouth and dog neck.Please check the size map and choose suiable size .Please double check before purchase.<br> HEAD STRAP:If your dogs would never pull off the muzzle by his paw,you can cut the head strap off.Thus you can wear the muzzle more quickly<br> ATTENTION: Our dog muzzle do not suitable for short snout as:Pitbull mix,boxer,dutch mastiff,affenpinscher, boston terrier and so on. Note: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!