The LED light can make vehicles and people see your dog well in the dark. The plastic tube part can be rub in any shapes which won't affective the light of this collar. The collar is made of rubber and plastic, it is very durable. There are three sizes of collars, the circumference is 35cm, the circumference is 50cm and the circumference is 70cm. The collar is suitable for outdoor activities, like hiking, running and so on. Item Name: LED Dog Collar Material:Plastic,Rubber Size: Red,50cm: 16.8cmx16.6cmx1.8cm/6.61inx6.54inx0.71in Red,35cm: 14.7cmx13.2cmx1.6cm/5.79inx5.2inx0.63in Red,70cm: 23.6cmx23.5cmx1.7cm/9.29inx9.25inx0.67in Blue,50cm: 16.9cmx16.8cmx1.7cm/6.65inx6.61inx0.67in Blue,35cm: 14.4cmx13.2cmx1.6cm/5.67inx5.2inx0.63in Blue,70cm: 24cmx22.9cmx1.8cm/9.45inx9.02inx0.71in Yellow,50cm: 17.1cmx16.4cmx1.7cm/6.73inx6.46inx0.67in Yellow,35cm: 14.2cmx12.9cmx1.6cm/5.59inx5.08inx0.63in Yellow,70cm: 25.2cmx20.2cmx1.7cm/9.92inx7.95inx0.67in Green,50cm: 18.6cmx17.2cmx1.8cm/7.32inx6.77inx0.71in Green,35cm: 13.9cmx13.2cmx1.6cm/5.47inx5.2inx0.63in Green,70cm: 23.7cmx23cmx1.6cm/9.33inx9.06inx0.63in Pink,50cm: 16.5cmx16.4cmx1.8cm/6.5inx6.46inx0.71in Pink,35cm: 14cmx12.9cmx1.7cm/5.51inx5.08inx0.67in Pink,70cm: 24.6cmx22cmx1.7cm/9.69inx8.66inx0.67in Orange,50cm: 17.8cmx16cmx1.6cm/7.01inx6.3inx0.63in Orange,35cm: 14.6cmx13.5cmx1.7cm/5.75inx5.31inx0.67in Orange,70cm: 24cmx22cmx1.7cm/9.45inx8.66inx0.67in Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 X USB Charging Cable 1 X LED Dog Collar