2P folding propellers Flexofold Sail Srive. Flexofold manufactures high-performance folding and three-bladed propellers to match and exceed the performance of fixed propellers. A sailboat propeller must convert the engine power into thrust as efficient in forward as in reverse and have a minimum drag to sail faster under sails. ATMB Marine provides advice and recommendations for Flexofold propellers according to applications. A form for calculation and definition is available on our website. Flexofold propellers are designed according to the following specifications: Do not generate noise or vibration. Be reliable and reasonably priced. Must not hang ropes and drifting objects. Need little maintenance. Be made with quality materials. Flexofold propellers have proven themselves in terms of