Well made but very heavy ~30gms! Uses an aluminium centre-shaft with 3mm (perhaps 1/8"?) hole. Grub screws being used to hold the centre-shaft to the motor-shaft. A large steel nut holds the cone to the shaft and this is where much of the weight comes from. Suspect this prop is purpose built for a plane needing a forward counter-balance weight.
I removed the blades and used on a Kinetic (glider that used to be sold on HK) prop-hub, this makes for a light weight 6x3 folding prop.