These 31mm props are just customized for 65mm brushless drones that have a 1.0mm or 0.8mm motor shaft. The recommended motors for 1.0mm are 0603 motor, 0703 motor and 080X motor like 0802 motor. Besides, here are the 31mm 3-blade props (1.0mm Shaft) and 31mm 3-blade props (0.8mm Shaft) for your choice. Specification Item: 31mm 4-blade Props  Material: PC Center Thickness: 5mm Prop Disk Diameter: 31mm Center Hole Inner diameter: 0.8mm / 1.0mm Prop Width: 5.71mm Weight: 0.31g Colors: Blue / White / Grey Recommended Parts Gemfan 31mm 4-blade Micro Whoop Propellers (1.0mm Shaft) Drone: Beta65X / Beta65 Pro 2 / Beta65 Pro / Meteor65 Frame: Beta65 Pro frame / Beta65X 2S frame / Meteor65 frame Motor: 0603 motors / 0802 motor / 0703 motor Gemfan 31mm 4-blade Micro Whoop Propellers (0.8mm Shaft) Drone: Beta65S Lite Brushed V3 Frame: Beta65S Lite Brushed frame Motor: 7x16mm Brushed Motors Package 2 * CW 31mm 4-blade Micro Whoop Propellers (1.0mm/0.8mm Shaft) 2 * CCW 31mm 4-blade Micro Whoop Propellers (1.0mm/0.8mm Shaft) or 8 * CW 31mm 4-blade Micro Whoop Propellers (1.0mm/0.8mm Shaft) 8 * CCW 31mm 4-blade Micro Whoop Propellers (1.0mm/0.8mm Shaft)