VarioProp Hub & Blade Systems give you 2, 3, 4and 5-blade configurations with an ingenious system for adjusting blade pitch in the hub. HUB 8B weighs 12 grams on average and allows adjustment from 3 inches to 10 inches of pitch. The 8B HUB comes in variations to fit 3.2mm, 4.0mm, 5.0mm, and 6.0mm motor/gearbox shafts.
The "Speed" blades for 8B-sized hubs are particularly intended for faster models using direct-drive motors like AXI 28 Series, Mega 22 Series, and similar. Depending on motor and gear ratio, the "speed" props may be the best solution for a geared system, too, if the target rpm is high.
The Scale blades 9.7" can also be used either direct-drive or geared, but the larger sizes are most appropriate for geared systems.