The oil slick bootie is not new, but Assos figured out how to make it better. The idea is simple; you need a stretchy, impermeable fabric with an opening in back for your foot, an opening on the bottom for your cleat, and an opening for your heel. This is Assos' rainBootie, a waterproof foot covering done as it should have always been done. Originally, this style of shoe covering was a crossover from the early days of aerodynamic clothing. Coated skinsuits, gloves, and booties were thought to be faster than ordinary skintight fabrics, and similar materials were used in clothing for track events. One day, someone figured out the booties could work as rain protection. Problems were several. First was durability. They usually wore out quickly because they weren't designed for miles and miles of use. There was no zipper in back, no heel cutout, and the material wasn't as stretchy as plain spandex. A practical problem was that they were seamed down the middle, so they weren't much protection from wet roads.Assos solved these problems. The material in the main body is their 434 stretch fabric coated with a polyurethane they developed that has incredible elasticity. The rainbootie has a rear-entry locking waterproof zipper to make entering and exiting easy. The toe, heel, and cleat areas are all covered in reinforced nylon. The seam no longer is in the center. There is now a front panel that runs back to the ankle and to the two smaller rear side panels. By eliminating the seam down the middle, the potential for leakage across the top of the foot is also eliminated. And furthering the sealed-in quality, there is a tight gripper around the top cuff keeping the water dripping in to a minimum.The Assos rainBootie comes in Black, and the zipper has a reflective stripe alongside it. There are three sizes: 0, I, and II.