Higher spline counts provide more surface area for the axle to transfer the torque load from the differential. There's also the added benefit of a larger physical size for an axle with more splines. At least in most current axles with spline teeth of equal size. The spline count is critical when it comes to fitting a prop. They are the little teeth on your propeller's shaft and inside the hub. Key Features: The splines have little backlash and are coated with a special polymer for long life, minimal friction, and inexpensive maintenance (reduced sliding force). Standard spline parts are sealed and lubricated at the factory. VS-44 Spindle length: 2.930-inches (~2 15/16-inches) Flange Dia.: ** Rubber O.D.: 1.475- inches Max. Inside Dia.: 0.714- inches Uses Wear Ring: none Rubber Duro: 70 Spline count: 10 spline Engine Application Mariner - Mariner 25 hp 1980-1984; 28hp 1976-1979; 30hp 1979-1990 Yamaha - Yamaha 20-30 hp 1976-later Specifications: Brand: HMS Hubs SKU: VS-44 UPC: VS-44 Weight: 0.25 LBS G/C SIZE: 3.25 DRIVE TYPE: 10 Spline HUB TYPE: Rubber