Crash tested, tensile-strength tested, and dynamically tested for safety. * Secures dog in the car to avoid driver distraction - use with any vehicle seatbelt * 5 adjustment points and broad padded chest plate for a comfortable fit * Steel nesting buckles for improved strength * Great for walking * Size M fits dogs 25?50 lb (11?23 kg), with 16?25" (40?63 cm) neck and 18?28" (46?71 cm) chest * extra ring in front helps control dogs who pull