Features:1.The collar size can be adjusted, and the push button can control the collar size well until it is adjusted to the proper position, which is very convenient and safe2.Built in electricity storage device, the continuous luminous effect is 60-70 hours, and it can be used for about 1 month under normal conditions.3.The product is made of steel by grinding and has bright luster, wear resistance, tensile resistance, breaking resistance and other characteristics.Description:With exquisite SMT technology, solder paste and reflow welding, the joint is stronger, more reliable and durable.Specifications:Color:blue,red,green,pink(optional)Material:Polyester webbing, fishnet mesh transparent surface, super bright light guide flat fiber (new material)Size:S,M,L,XL(optional)SIZE Full Length Neck Width cm cm cmS 37 20-37 2.5M 50 32-50 2.5L 60 42-60 2.5XL 66 48-66 2.5Package Included:1 x dog chest strap1 x OPP bag2 * CR2032 button batteryNotes:1. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the pictures.2. Please allow slight dimension difference due to different manual measurement