Sash cams are used in hung windows that use channel balances, so the sash's track slides up and down properly They mount to the top side edges of the moving vent, 2 per window and sizes can vary per manufacturer Dimensions of theses sash cams are 1-1/2 inch tall, 7/8 inch wide at the top, 5/8 inch wide on the bottom and 31/32 inches deep They can become brittle with age and UV exposure and break, rendering the window channel balance disabled, best to replace both at the same time Please refer to the line art drawing for dimensions and compare with your original item before purchasing (Not Universal)