The Pet Life 'Sea Spot Sun' UV Protectant Adjustable Fashion Mesh Brimmed Dog Hat Cap is composed of 100% breathable Micro-mesh that offers high-levels of ventilation. Sports a 360 degree brim design with a fashionable spotted bow-string that wraps around the hat and ties elegantly. This dog hat features an adjustable jaw string below the neck line that properly adjusts and should lightly secure around the head accordingly. Additionally this hat features dual sided ear holes for premium comfort. The brim of the hat is meant to protect the head and damage to the sensitive eyes from direct sun view and from the suns powerful and harmful rays by assisting in shaded UV protection. Features subtle embroidery with reinforced stitching all around for added durability. Water resistant and Machine washable. Available in Multiple Sizes and Colors. SIZING MEASUREMENTS: In Inches MEDIUM: Inner Hat Diameter: 4.5" Head Circumference: 14.6" (Small to Medium sized breeds) LARGE: Inner Hat Diameter: 5.5" Head Circumference: 17.3" (Medium to Large sized breeds).