It also comes with a two piece reflective collar rather than a black one for the standard Puplight. Made of polycarbonate plastic and nylon. Water Resistant - if it starts to rain or if light gets splashed. Comes with adjustable elastic band worn below existing collar: easily slips over the dog's head or use side release buckles. keeps light from moving when leash is pulled to one side. Includes extender strap for large dogs. Fits necks 8" to 26".