Ultimate Flaps are constructed using nearly indestructible semi-ridged material. Curbs, rocks and logs will flex the flap, but the mud flap will return to its original position. Extremely cold weather is not a problem for Ultimate Flaps. Our material stays flexible up to -42 degrees below Fahrenheit. Getting built-up snow and ice off Ultimate Flaps takes a gentle kick on the back side. Ultimate Flaps stay rigid but conform to the wheel well of the vehicle without grappling between fasteners. Fender flares on today's pick-ups are made of molded plastic and attach to the inner fender well. The flare is not suitable to mount mud flaps. Flaps must be attached to the sheet metal that can be 3 inches from the sheet metal of the fender or pick-up box. Ultimate Flaps are ideal for installation with fender flares, keeping a tight fit between flare and flap. The flap can be positioned to give a nice straight line from flare vertically. Ultimate Flaps use a grooved material to direct mud snow and rain down and away from your vehicle and whatever you tow. Ultimate Flaps won't sail back while going down the road like rubber flaps. Additionally, our mud flaps won't be torn off by backing up in deep snow. Mud with clay content that builds up won't make Ultimate Flaps rest against your tires because of the weight of the built-up mud. Ultimate Flaps are great for lifted vehicles — especially those needing additional coverage for larger tires. Plates/weights are attached to mud flaps with stainless studs that are welded to the plate, then torqued with stainless steel locking nuts. Made with pride in the USA.