These selections only available on the VP9, VP40 & VP9SK models.
 
If you have the Holosun EPS or EPS Carry, select the Holosun 407K507K Optic Cut option.
 
If you have a Trijicon SRO, choose the Trijicon RMR cut.
If you have a Holosun 508T, choose the Holosun 507/407 cut.
 
If you have a Roemo 1 PRO, select the Deltapoint Pro cut. The Romeo 1 and Romeo 1 Pro are not the same. 
 
If you have the original Vortex  Defender, slect the Shield RMSc cut and put in the notes section at checkout that you have the original Defender. If you have the Defender ST, select the Vortex Defender ST option.