I am a novice RC plane builder and got a MKS 48" Extreme Flight plane from a friend along with a BL15 eflite motor. I then bought a 12x6 prop as recommended by Extreme Flight's website. I am now trying to mount the propellor to the motor and seem to be missing adapter pieces since the motor shaft is a 5mm smooth shaft and the prop has a 6mm hole. I assume there is some kind of adapter system? I built & flew my own plane from Flite Test already but that came with everything I need. This build requires some fumbling and my local club is not active right now because it's winter! Please help me find what I need! Thanks for any info.

I tried posting links but this site won't let me yet since I'm new.

The motor is a BL15 1260kv by eflite
The prop is a 12x6 beechwood electric prop by Falcon
The plan is by Extreme Flight and is a MXS 48" wingspan