Bought my topper for $100 no idea what brand and in pretty bad condition. Bought these after some measurements of unassembled burned out leaking racks and they work exactly as they should, so far so good. The installation was so easy that a child could handle it, and the force of the piston is not so great that it was difficult to control the opening of the rear window. The product was also shipped quickly and, if I remember correctly, received before the estimated delivery date.