The gemfan 5040 propellers have raise the standard, and are used by some of the best fpv pilots and racers with 210mm through 280mm size quadcopters (quad) and multirotor drones. Made from quality abs plastic, these propellers offer the performance that top pilots have come to love, yet delivers the reliability that the causal hobbyist expects. The matte black color of the propeller gives your racing drone a sleek and racy appearance. High performance and reliability doesn’t have to a high price tag, these propellers are affordable and is within any flying budget. Specification: material: ABS plastic length: 5 inches screw pitch: 4 center hole diameter (hub): 5 mm weight: 2.0 Grams (a united states penny is 2.5 Grams) color: matte black compatible motors: cobra 2206,t-motor 2204 e-max 2204, sunnysky x2207s, sunnysky x2206, and other motors compatible frames: ZMR 250, QAV 250, h250, FPV 250, vortex, and other 210mm to 300mm size airframes package includes: 4 clockwise propellers 4 counter clockwise propellers 8 adapters for 4mm hub 8 adapters for 3mm hub 8 adapters for 2.5Mm hub (you need 2 clockwise and 2 counter clockwise propellers to fly 1 quad, this package includes enough propellers to fly 2 quads.).