Have one or two vertical, gliding sashes which operate by sliding one sash vertically past another. Tilt-out upper and lower sashes makes cleaning and inspecting weatherproofing strips simple and convenient. The standard unit has UPVC frame, window latch, snap on insect screen, spring balance hinge and a single, glazed, grey anti sun glass, these popular and traditionally styled windowsmoffer medium to hih ventilation and the multiple chambers within the frame creates a thermal barrier to reduce air loss and heat transfer, they are ideal for high traffic areas such as adjoining walkways, porches and patios.