Bought the visible pulley covers for all the sash windows in the house. Simple enough product, not particularly attractive to look at, but more or less out of sight when fitted. However, they are effective at stopping the draughts that, in the right weather conditions just seeped cold air into the house. Couple of points for Reddiseals; firstly the plastic blocks the that clip around the pulley ropes are left and right handed, but I got a set that were all the same "handedness", so I had to make some minor modifications for them to fit. And secondly, it would have been good if the pulley covers came complete with small wood screws to fit them with. I would recommend Reddiseals and the sash window pulley covers.