WeatherTech All-Weather Trim to Fit Rear Rubber Mats for Toyota Prius, Grey Deeply sculpted channels trap water, road salt, mud and sand Won't curl, crack or harden in sub-zero weather Have anti-skid ridges Made Of 16 lbs. Of Pliable Natural Rubber, with Anti-Skid Ridges to revent shifting Will Not Curl/Crack/Harden In Sub-Zero Weather and holds up to 1 1/2 quarts of liquid without spilling