the sill brushes and standard SL brushes from gardiners are all lighter and all have their uses for f/s/g cleaning,conny roofs and solar panels.i find these brushes a lot more hard wearing albeit i dont use them as much as the extremes.
The SL brushes are heavier, the weights quotes on the website do not include the socket. I've weighed all my SL brushes, flocked, medium mixed and stiff, and the all weigh in at roughly 300g.
The cill brush weighs roughly the same when a socket is fitted, but will have less cleaning power and I find them too unstable when using a swivel.
To compare the weight of the brush to the quoted figures on Gardiners website, the aerial brush weighs roughly 225g without the socket.