How to install?

A quick learner from San Francisco says:
I just purchased a large amount of these to stop some of our double hung windows at a boutique hotel but am not exactly sure how these install. Can anyone explain how these work? Also, is there any information on what size screws are needed here (going into wood frames)?

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Bob from SWISCO responded:

Hello there. The first thing to note is that the 26-275 limit locks are only used on Horizontal sliding windows. They don't work on Double hung windows like you say you have. For a limit lock that could work on hung windows, see our 26-387 . The video below shows how to install it. 

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