All Four Paws 6-Inch Chill Pet Collar, Medium 6" Neck Diameter Made of non-rigid silicone that won't loose it's shape. Keeps dogs cool for up to 2 hours Unique hidden buckle keeps the collar fastened and comfortable. Easy to wipe clean. Ideal for playing at the park, going for a walk or just hanging out at home! 6-inch Neck Diameter The Chill collar is made with non rigid silicon and will never loose it's shape Whether on a walk, playing at the park, or chilling at home, the Chill Collar keeps your dog cool for as long as 2 hours Unique hidden buckle easily keeps the collar fastened Easy to wipe clean