These four- propellers are tailored for precision and functionality, providing and stability for model aircraft and other motorized creations. Their lightweight yet sturdy design supports smooth operation, making them a reliable choice for enhancing performance in technological and scientific experiments. Features -Color:Yellow -Material:Plastic -Size:3.90X3.90X0.80cm/1.53X1.53X0.31in -Durable construction: built to last, these propellers are made from durable materials that withstand the rigors of model building -Optimal performance: the 1.5 mm hole diameter ensures optimal performance, providing stable and efficient power to your models -Universal fit: the 40 mm size is compatible with a variety of models, making it a versatile addition to your model building tool -Quiet operation: designed to reduce noise, the four configuration ensures a quiet and smooth operation for your models -Practical for model enthusiasts: whether you're building model airplanes or ships, these propellers are practical for enhancing your diy projects Package list: 5 pcs x 20pcs x micro propeller