Scope Chap sprcifically fit for the Vortex AMG optic.  The product will fit around the defender scope caps from Vortex if you use those, or fit pretty close to the front edge of the scope if you use Tenebraex brand caps.  
 
WITH SUNSHADE option will add 3.0 inches length to the Scope Chap (finished at 4.75" straight section length).