I purchased this Ops Core ballistic helmets and I am showing how I set them up. I also show the differences in dimensions between the helmets. I will include where I purchased each one of these helmets. The rest of the accessories were bought from hcctac.com.

NOTE: the Ops Core XP is a HIGH CUT helmet and will need a specific kind helmet cover and the SF/XR helmets are the SUPER HIGH CUT. Please be aware of this when purchasing the proper fitting cover. Here is a link of an option for the Ops Core XP helmet cover:
https://agilitegear.com/collections/h...

Ops Core XP:
https://tnvc.com/shop/opscorefastx...

Ops Core Fast SF Helmet:
https://www.customnightvision.com/pro...

Ops Core Fast XR:
https://www.hcctac.com/products/fast...

Agilite Helmet Covers:
https://agilitegear.com/collections/h...