Shaun,
I don't know if the brush is Hard or soft. All I know is it scrubs a bit better than a standard Gaz h20 brush (although Gaz has hard soft or medium brushes).
As for scratching the glass
. I don't think any brush worth considering for WFP will scratch glass.
As for fitting with jets:
All I have done is:
1. About a meter of fish tank air tube (3mm id and 5mm od)
2. 3 6mm joining barbs
3. A T connector.
First, about 1" 1/2 in from either end of the brush head pull out about half a dozen clumps of bristles. enough so as to fit the jets in and allow flow of water.
Then drill, from the bristle side of the brush 2 6mm holes for the jets.
Then, take 2 of the 6mm barbs a pair of wire clippers and snip off one of the barbs on each. This makes 2 jets!
Then cut 2 15cm lengths of the Fish tank tube and squeeze on to the jet barbs left.
Then slide the tubes thruogh each of the holes in the brush and push the jets into place. They should be a tight fit and pushed up to the wide bit on the barbs.
Then cut about 30cm of the Fish pipe. Connect the three lengths together with the T connector.
Then push on the 3rd 6mm barb and connect to your pole tube.
The brush should screw onto your pole screw, it does fit an Unger adapter (a bit stiff, but all the better!).
Try it!
It'll only cost you about £6 - £7
£3.98 for the Melody Brush from Tesco
£1 for a meter of tube
£1 for the 3 Barbs
50p for the T conector.
David