<b> How are glass shades measured? </b><br> <br> The fitter is the outer diameter of the lip which is inserted into the fixture’s shade holder. This <br> will measure a little less than the fitter size so it can fit into the shade holder of the same <br> measurement. <br> <br> The height of a glass shade is taken from the base of the fitter lip to the bottom of the shade. <br> <br> The width is measured across the widest portion of the shade. <br> <br> <br> <b> How to install it? </b><br> <br> This glass is held in place with 3 screws on the original fixture. Just twist the screw into the <br> groove on the light fixture (by hand). <br> <br> <br> <b> Screws not included. </b><br>