Allen’s MSP series is the most popular series in their ride-on trowel line up. You can now choose between the MSP445 (manual steer) and the MSP455 (Power Steer). Both models offer a powerful gasoline engine, Super Heavy-Duty Gearboxes and Spiders to provide a great weight to-horsepower performer for larger contractors.nThe MSP445 and MSP455 are both easy to control and steer. Standard features include an electric-powered spray system and built-in cup holder. Both models are powered by the Kohler 37HP gasoline engine and both come with all of the standard features of an Allen ride-on trowel.