Acorn vinyl window stop/lock. How is it attached?

A home owner from ardsley ny says:
I am moving into a residence that has ACORN vinly clad alunminum windows. I am looking for a stop where I can open the window to a certain height and leave it there without it being opened any further. in looking at the diagram of the 55-063 I cannot figure out how it attaches and how it operates. any help would be appreciated.
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Paul Sr. from SWISCO responded:
The #55-063 stop is used on the aluminum Acorn windows, not the vinyl windows. What you need is a vent lock. If your window does not have an existing vent lock (broken or missing), most of the vent locks found on will not work for you because they are for replacement and not a new application.
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Mike from SWISCO responded:
We just added the new 26-387 Vent Lock Kit, which can be used with windows that don't have a vent lock. The 26-387 can work with any hung or sliding window.

This video should help you to see how it is attached to the window:

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