Window rollers are designed to make it seamlessly smooth and easy to open and close windows that slide open left to right. These rollers are placed near the bottom edge of the window inside the frame and allow for substantial light and air to enter through the window fixture. They are easy to install and allow for an unobstructed view through the window, as well. With simple, regular maintenance and cleaning, they remain in good working condition and allow for ease of window use for years.