I have got a black pro-window dual trim brush and have never fitted it,when i apply it to glass by hand the outer longer bristles seem to bend over and cover the inside shorter bristles so they might as well not be there.
Now somebody tell me thats not true.
Its possible to manipulate the brush to get the inner bristles working but its not easy and thats at arms length!,no ,i repeat no chance on the end of a pole.
I am pig sick of the inefficient crap that is on sale,its no wonder wfp has a bad name around the houses.
Been there, done it all before. Recently had another stab at it & tried some different brushes. Verdict- No development at all. Same old, same old. :

I'll be sticking with Gardiners
Been using Gardiners for about 3-4 years now, in that time there have been massive developments, all in the right direction. The only product I didn't get on with was the superlite single trim mono brush-standard splay.
The new 15 degree DT semi flocked is the business IMO. I've got the new carbon goosneck & Xtreme brush quick release system all ready to go but can't get out because of the snow!

If you want a real laugh, check out Unger's new multilink system!
