function openWindowCustom(url, name, param) {popupWin = window.open(url, name, param);popupWin.focus(); };Rubexs 135-300hp Four-Blade Aluminum Propeller is made using a state-of-the-art squeeze-casting process to make its aluminum propellers stronger and tougher than traditional die-cast props. Squeeze casting produces propellers with finer grain and much less porosity than die-casting and equals thinner yet stronger blades. This provides outstanding acceleration, cruising and top speed. Use with compatible Rubex Hub Kit (sold separately). Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Aluminum Props.