I have reduced the weight of this brush by 100grms using some parts from a worn out supalite brush, which took no more than 10mins to do.
1) Cut off the stem which your pole screws into and replace with the one from a supalite brush.
2) Replace the existing pencil jets with the ones from the supalite.
3) Drill 2 holes with a wood bit ensuring that you go about two thirds of the way through the head. The pointed end of the drill bit will go right through but will only make a small hole which can be sealed with clear mastic.