it goes in a double hung residential window and inserts into the spring that controls the window up & down

A quick learner from Ooltewah, TN says:
need to purchase the part in the attached photo
User submitted a photo of a tilt pin.
Profile picture of Tom
Tom from SWISCO responded:
Thank you for contacting us. Please look at product 20-016 tilt pin. We believe this is what you need.
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