GEMFAN 5X3 3 BLADE PROP ORANGEGemfan 5x3 3 Blade Propellers for Electric Flight. Specifications: This shape is constructed for direct drive applications. Material: Black plastic construction Center hole diameter: 5mm Adapters rings include: 3mm/3.17mm/4mm Color:Black/Orange/Green Compatible:Use For RC Plane or Multi-copter