Top horizontal section along the curve: 9 & 3/8″
Top horizontal section height (top to bottom): 1 & 3/4″(ends) to 1 & 1/2″ (toward middle)
Middle vertical section from top to bottom: 3 & 1/4″
Middle vertical section width (left to right): 3/4″ (bottom) 2 & 1/4″ (were it meets horizontal section)
REMEMBER: T-Visors are installed from the inside of the helmet so a little bit of overlap is a good thing.
Fits Episode III Clone Trooper Helmets as well as others.