Shop our range of high quality replacement Window Gearboxes from top brands such as ERA, Mila, Saracen and Vita to name but a few. The window lock gearbox is the part that is driven by the window handle, enabling you to open, close and lock your window. This part can occasionally fail and can often be replaced with relative ease. We have a team of friendly, expert staff who can help with choosing, measuring or fitting any of our products. Visit our technical help page to find the different ways of contacting us with any query.