Strauss Bicycle Speedometer, (Black/Red) and Gel Seat Cover (Black) This bicycle speedometer is waterproof and works great on rainy days as usual when riding Easy to install and use it is easy to follow instructions, great basic functions of the speedometer and very specific tire size that enable accurate calculations. Portable size, light weight, wide application this bike odometer is only for 1.8 x 1.8 inches (l x w) and 0.18 lb, which is easy to carry and save your space High density sponge slip mat comfortable and soft, ergonomic design Thick pad with shock absorption function and soften the riding, inner side the seat cover with gel-point, ensuring the seat does not slip after installation With 3d anti-slip granules on the back, necessary tool for your outdoor cycling