I find these are a little noisier than the 4 blade but better thrust. Good quality. I will buy more.
Model Number: 1636 Number of blades: four leaves Pitch: 3.5in Material: PC Inner hole inner diameter: 1mm/1.5mm two sizes are available Paddle disk diameter: 40mm Center thickness: 5.2mm Maximum blade width: 7.46mm Adaptation motor: 1103-1105 Recommended motor: 1103 Shipping list: Positive paddle 4 Anti-paddle 4
Dimensions and Weight
Product weight: 0.0006 kg Package weight: 0.0060 kg