Marvin Elevate Replacement Sash Lift

Pluses and Minuses

We tried various window pulls and these Marvin ones were clearly the best. Probably because our Marvin windows seal tightly they are difficult to open and close, so installing two pulls on each lower pane of double-hung windows is strongly recommended. Query, however, why these pulls come with screws that are much too long and have heads that don't match the color of the pulls, nor the color of the inside of the windows?

Martin Elevate Replacement Sash Lift

My window installer does not think it may fit; we thought this was a option for these windows (we had two of the 'Elevate' windows installed). One window works (goes up and down effortlessly) fine, the other is impossible for my wife to operate, very tight and she is unable to lift, pull or lock the window. Also, why is this called a 'Replacement' lift? There was nothing to replace on the window, it came without any lift hardware. We are waiting for Marvin to offer a solution. This is also a security issue as if I am not around, my wife can't lock it.