The window cling is 3.5 in with rounded corners
The vinyl layer is 3in on the biggest side-exact placement of the vinyl will very 
How to install-
Clean window/glass where you would like to place the cling
wet the window/glass glass with soapy water
remove the film backing (located on side opposite the vinyl)
Put on window/glass 
Squeeze out any air or water using a smooth tool like a credit card