Just like the Killflash, the scope extender helps to mitigate reflections of the scope lens that can give a away your position.
Combination of these makes it impossible to get any reflections at all. In addition to this, both of them protect the scope body itself from accidental damage and bb impacts.
This Scope Extender fits on: https://www.canadiancartel.ca/collections/novritsch/products/novritsch-scope-set
It's slim construction doesn't add much weight to your scope setup. Killflash and lens caps can still be used with the scope extender.
Besides all of the benefits described above the scope extender also adds a lot to the overall aesthetics of your rifle setup. It's just makes your rifle look much cooler in my opinion.