The Nautilus REPLACEMENT SEAT is designed specifically for upright stationary bikes in the U616/U626/U686 series. This set includes a black saddle seat with medium to hard padding, making it suitable for gym and training activities. The seat is 10.5 inches long and 2.25 inches tall, weighing 2 pounds and 1 ounce. Made by Nautilus Residential, this seat is a reliable and comfortable option for your stationary bike.