Xtreme Production CNC Machined 350 QX / 350 QX2 Aluminum Prop Adapter Set Included: 4 - Xtreme Production Aluminum Prop Adapters, 8 - M2.5 x 6mm socket cap screws To be used with the Xtreme Production Blade 350X Carbon Fiber Blades CNC Machined from Billet Aluminum Perfectly Alignes Prop to Motor Very strong and light weight