These window sash lifters are designed for double-hung windows and provide reliable mechanical support during operation. Each lifter features a die-cast zinc construction for strength, density, and resistance to deformation under repeated use. Measuring 4 in. Wide by 3/4 in. High with a precise 3-5/16 in. center hole spacing, they fit standard window frames without modification. The white finish blends seamlessly with light-colored frames, supporting clean visual integration. They assist in bearing the sash weight, reducing manual effort when raising or lowering the window. Installation relies on existing screw holes and original hardware to maintain structural integrity and alignment. No screws are included, as compatibility depends on the host window s original fasteners. This set contains 4 units, sufficient for replacing both lifters on 2 typical double-hung sashes.