This plastic sash cam fits onto the upper top sides of the window (vent) that is sliding up or down. The sash cam and window then rest on the top guide of the sash balance. It has dimensions of the top being 1 inch wide by 5/8 inch deep and 1-5/16 inch tall. Width of this top guide needs to fit correctly in the window's track frame in order for it to slide up or down properly, and the depth allows the window to correctly rest on the top guide of the sash balance.
The factory sealed sash cams are used in hung windows that use channel balances
Each sash cam insert mounts to the top side edges of the moving vent, 2 per window
They actually engage and push the channel balance top guide, moving the balance with the window
Over time they can become brittle with age and UV exposure and break, rendering the window channel balance disabled
Please refer to the line art drawing for dimensions and compare with your needs before purchasing